Method for preparing silicone hydrogels

ABSTRACT

The invention provides a contact lens manufacturing method for cast-molding of silicone hydrogel contact lenses having enhanced oxygen permeability without adversely affecting desirable lens mechanical properties (e.g., modulus). A method of the invention comprises adding a small amount of a radical scavenger (e.g., H-TEMPO) in a polymerizable composition for cast-molding of SiHy contact lenses) to provide the resultant polymerizable composition with a bi-phase curing profile at a curing temperature of from about 45° C. to about 100° C. With such a bi-phase curing profile, the resultant polymerizable composition can be thermally cured at the curing temperature to form a SiHy contact lens having an oxygen permeability higher than that for a polymerizable composition having the substantially identical composition excepting being free of any radical scavenger.

This application claims the benefit under 35 USC § 119 (e) of U.S.provisional application No. 62/680,001 filed 4 Jun. 2018, hereinincorporated by reference in its entirety.

The present invention is related to a method for preparing siliconehydrogel material with enhanced oxygen permeability without adverseimpacts on lens mechanical properties.

BACKGROUND OF THE INVENTION

Silicone hydrogel (SiHy) contact lenses are made of a hydrated,crosslinked polymeric material that contains silicone and a certainamount of water within the lens polymer matrix at equilibrium. They areincreasingly becoming popular, because of corneal health benefitsprovided by their high oxygen permeability. Although incorporation ofsilicone in a contact lens material can provide the contact lens withhigh oxygen permeability, it can also have undesirable effects on thehydrophilicity and wettability of SiHy contact lenses, because siliconis hydrophobic and has a great tendency to migrate onto the lens surfacebeing exposed to air. It would be desirable to have a manufacturingprocess for producing SiHy contact lenses with enhanced oxygenpermeability without adverse impacts on desired mechanical properties.

U.S. Pat. No. 7,671,156 discloses a bulk polymerization method formaking SiHy materials suitable for lathing at room temperature, in whicha relatively low amount (e.g., less than about 1%) of a chain transferagent can be added in a polymerizable composition so as to provide aresultant silicone hydrogel material with a reduced elastic moduluswhile increasing or minimally impacting oxygen permeability.

U.S. Pat. No. 8,501,833 disclose that by adding an organonitroxide to apolymerizable composition for making SiHy materials in an amount to havea selected ratio of percentage by weight of the organonitroxide to theradical initiator in the polymerizable composition, the polymerizationcomposition can be cured in tubes at an elevated temperature to formSiHy rods which are substantially free of defects, such as, cracks andvoids) and have consistent properties (e.g., oxygen permeability, ionpermeability, water content, elastic modulus, and/or elongation).

SUMMARY OF THE INVENTION

The present invention, in one aspect, provides a method of making SiHycontact lenses. The method of the invention comprises: (1) obtaining apolymerizable composition which is clear at room temperature, whereinthe polymerizable composition comprises (a) at least onesiloxane-containing vinylic monomer, (b) at least one polysiloxanevinylic crosslinker, (c) from about 15% to about 55% by weight of atleast one hydrophilic (meth)acrylamido monomer having 3 to 8 carbonatoms, (d) from 0 to about 25% by weight of an organic solvent having 2to 8 carbon atoms relative to the total weight of the polymerizablecomposition, (e) at least one thermal free radical initiator, and (f) atleast one radical scavenger present in an amount for providing thepolymerizable composition with a bi-phase curing profile determined byusing thermal DSC (Differential scanning calorimetry) to polymerizationkinetics of the polymerizable composition at a curing temperature offrom about 45° C. to about 100° C. as function of time; (2) introducingthe polymerizable composition into a lens mold, wherein the lens moldcomprises a male mold half having a first molding surface and a femalemold half having a second molding surface, wherein the male and femalemold halves are configured to receive each other such that a mold cavityis formed between the first and second molding surfaces when the mold isclosed; (3) curing thermally the polymerizable composition in the lensmold in an oven at the curing temperatures for at least 30 minutes toform an unprocessed silicone hydrogel lens contact lens; (4) separatingthe lens mold into the male and female mold halves, with the unprocessedsilicone hydrogel contact lens being adhered on a lens-adhered mold halfwhich is one of the male and female mold halves; and (5) removing theunprocessed silicone hydrogel contact lens from the lens-adhered moldhalf.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a mold according to a preferredembodiment of the invention.

FIG. 2 illustrates schematically a process for separating the male andfemale mold halves of a lens-forming mold according to the invention andan apparatus for performing a method of the invention.

FIG. 3 illustrates an ultrasonic welding system.

FIG. 4 illustrates a flat ultrasonic horn seated on extended flat edgesurround the outer concave surface of the male mold half.

FIGS. 5A and 5B illustrate a convex ultrasonic horn is seated within theouter concave portion of male half mold half.

FIG. 6 illustrates a flat ultrasonic horn is sized to be approximatelythe outer diameter of the female mold half.

FIGS. 7A and 7B illustrate a concave ultrasonic horn seated within theouter convex portion of female half mold half.

DESCRIPTION OF PREFERRED EMBODIMENTS

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Generally, the nomenclatureused herein and the laboratory procedures are well known and commonlyemployed in the art. Conventional methods are used for these procedures,such as those provided in the art and various general references. Wherea term is provided in the singular, the inventors also contemplate theplural of that term. The nomenclature used herein and the laboratoryprocedures described below are those well-known and commonly employed inthe art.

“About” as used herein in this application means that a number, which isreferred to as “about”, comprises the recited number plus or minus 1-10%of that recited number.

A “hydrogel” or “hydrogel material” refers to a crosslinked polymericmaterial which has three-dimensional polymer networks (i.e., polymermatrix), is insoluble in water, but can hold at least 10% by weight ofwater in its polymer matrix when it is fully hydrated (or equilibrated).

A “silicone hydrogel” refers to a silicone-containing hydrogel obtainedby copolymerization of a polymerizable composition comprising at leastone silicone-containing monomer or at least one silicone-containingmacromer or at least one crosslinkable silicone-containing prepolymer.

As used in this application, the term “non-silicone hydrogel” refers toa hydrogel that is theoretically free of silicon.

“Hydrophilic,” as used herein, describes a material or portion thereofthat will more readily associate with water than with lipids.

The term “room temperature” refers to a temperature of about 21° C. toabout 27° C.

The term “soluble”, in reference to a compound or material in a solvent,means that the compound or material can be dissolved in the solvent togive a solution with a concentration of at least about 0.5% by weight atroom temperature.

The term “insoluble”, in reference to a compound or material in asolvent, means that the compound or material can be dissolved in thesolvent to give a solution with a concentration of less than 0.05% byweight at room temperature.

A “vinylic monomer” refers to a compound that has one sole ethylenicallyunsaturated group, is soluble in a solvent, and can be polymerizedactinically or thermally.

As used in this application, the term “ethylenically unsaturated group”is employed herein in a broad sense and is intended to encompass anygroups containing at least one >C═C< group. Exemplary ethylenicallyunsaturated groups include without limitation (meth)acryloyl

allyl, vinyl, styrenyl, or other C═C containing groups.

An “acrylic monomer” refers to a vinylic monomer having one sole(meth)acryloyl group. Examples of acrylic monomers includes(meth)acryloxy [or(meth)acryloyloxy]monomers and (meth)acrylamidomonomers.

An “(meth)acryloxy monomer” or “(meth)acryloyloxy monomer” refers to avinylic monomer having one sole group of

An “(meth)acrylamido monomer” refers to a vinylic monomer having onesole group of

in which R^(o) is H or C₁-C₄ alkyl.

The term “(meth)acrylamide” refers to methacrylamide and/or acrylamide.

The term “(meth)acrylate” refers to methacrylate and/or acrylate.

An “N-vinyl amide monomer” refers to an amide compound having a vinylgroup (—CH═CH₂) that is directly attached to the nitrogen atom of theamide group.

The term “terminal (meth)acryloyl group” refers to one (meth)acryloylgroup at one of the two ends of the main chain (or backbone) of anorganic compound as known to a person skilled in the art.

As used herein, “actinically” in reference to curing, crosslinking orpolymerizing of a polymerizable composition, a prepolymer or a materialmeans that the curing (e.g., crosslinked and/or polymerized) isperformed by actinic irradiation, such as, for example, UV/visibleirradiation, ionizing radiation (e.g. gamma ray or X-ray irradiation),microwave irradiation, and the like. Thermal curing or actinic curingmethods are well-known to a person skilled in the art.

A “hydrophilic vinylic monomer”, a “hydrophilic acrylic monomer”, a“hydrophilic (meth)acryloxy monomer”, or a “hydrophilic (meth)acrylamidomonomer”, as used herein, respectively refers to a vinylic monomer, anacrylic monomer, a (meth)acryloxy monomer, or a (meth)acrylamidomonomer), which typically yields a homopolymer that is water-soluble orcan absorb at least 10 percent by weight of water.

A “hydrophobic vinylic monomer”, a “hydrophobic acrylic monomer”, a“hydrophobic (meth)acryloxy monomer”, or a “hydrophobic (meth)acrylamidomonomer”, as used herein, respectively refers to a vinylic monomer, anacrylic monomer, a (meth)acryloxy monomer, or a (meth)acrylamidomonomer), which typically yields a homopolymer that is insoluble inwater and can absorb less than 10% by weight of water.

As used in this application, the term “vinylic crosslinker” refers to anorganic compound having at least two ethylenically unsaturated groups. A“vinylic crosslinking agent” refers to a vinylic crosslinker having amolecular weight of 700 Daltons or less.

As used in this application, the term “polymer” means a material formedby polymerizing/crosslinking one or more monomers or macromers orprepolymers or combinations thereof.

As used in this application, the term “molecular weight” of a polymericmaterial (including monomeric or macromeric materials) refers to thenumber average molecular weight unless otherwise specifically noted orunless testing conditions indicate otherwise.

A “polysiloxane segment” refers to a polymer chain consisting of atleast three consecutively- and directly-linked siloxane units (divalentradical) each independent of one another having a formula of

in which R₁′ and R₂′ are two substituents independently selected fromthe group consisting of C₁-C₁₀-alkyl, C₁-C₄-alkyl- orC₁-C₄-alkoxy-substituted phenyl, C₁-C₁₀ fluoroalkyl, C₁-C₁₀ fluoroether,C₆-C₁₈ aryl radical, -alk-(OC₂H₄)₁—OR^(o) (in which alk is C₁-C₆ alkyldiradical, R^(o) is H or C₁-C₄ alkyl and γ1 is an integer from 1 to 10),a C₂-C₄₀ organic radical having at least one functional group selectedfrom the group consisting of hydroxyl group (—OH), carboxyl group(—COOH), —NR₃′R₄′, amino linkages of —NR₃′—, amide linkages of —CONR₃′—,amide of —CONR₃′R₄′, urethane linkages of —OCONH—, and C₁-C₄ alkoxygroup, or a linear hydrophilic polymer chain, in which R₃′ and R₄′independent of each other are hydrogen or a C₁-C₁₅ alkyl.

A “polysiloxane vinylic crosslinker” refers to a compound comprising atleast one polysiloxane segment and at least twoethylenically-unsaturated groups.

A “linear polysiloxane vinylic crosslinker” refers to a compoundcomprising a main chain which includes at least one polysiloxane segmentand is terminated with one ethylenically-unsaturated group at each ofthe two ends of the main chain.

A “chain-extended polysiloxane vinylic crosslinker” refers to a compoundcomprising at least two ethylenically-unsaturated groups and at leasttwo polysiloxane segments each pair of which is linked by one divalentradical.

The term “fluid” as used herein indicates that a material is capable offlowing like a liquid.

The term “room temperature” refers to a temperature of about 21° C. toabout 27° C.

As used in this application, the term “clear” in reference to apolymerizable composition means that the polymerizable composition is atransparent solution or liquid mixture (i.e., having a lighttransmissibility of 85% or greater, preferably 90% or greater in therange between 400 to 700 nm).

The term “alkyl” refers to a monovalent radical obtained by removing ahydrogen atom from a linear or branched alkane compound. An alkyl group(radical) forms one bond with one other group in an organic compound.

The term “alkylene divalent group” or “alkylene diradical” or “alkyldiradical” interchangeably refers to a divalent radical obtained byremoving one hydrogen atom from an alkyl. An alkylene divalent groupforms two bonds with other groups in an organic compound.

The term “alkoxy” or “alkoxyl” refers to a monovalent radical obtainedby removing the hydrogen atom from the hydroxyl group of a linear orbranched alkyl alcohol. An alkoxy group (radical) forms one bond withone other group in an organic compound.

In this application, the term “substituted” in reference to an alkyldiradical or an alkyl radical means that the alkyl diradical or thealkyl radical comprises at least one substituent which replaces onehydrogen atom of the alkyl diradical or the alkyl radical and isselected from the group consisting of hydroxyl (—OH), carboxyl (—COOH),—NH₂, sulfhydryl (—SH), C₁-C₄ alkyl, C₁-C₄ alkoxy, C₁-C₄ alkylthio(alkyl sulfide), C₁-C₄ acylamino, C₁-C₄ alkylamino, di-C₁-C₄ alkylamino,and combinations thereof.

A free radical initiator can be either a photoinitiator or a thermalinitiator. A “photoinitiator” refers to a chemical that initiates freeradical crosslinking/polymerizing reaction by the use of light. A“thermal initiator” refers to a chemical that initiates free radicalcrosslinking/polymerizing reaction by the use of heat energy.

“Post-curing surface treatment”, in reference to a silicone hydrogelbulk material or a SiHy contact lens, means a surface treatment processthat is performed after the silicone hydrogel bulk material or the SiHycontact lens is formed by curing (i.e., thermally or actinicallypolymerizing) a SiHy lens formulation. A “SiHy lens formulation” refersto a polymerizable composition that comprises all necessarypolymerizable components for producing a SiHy contact lens or a SiHylens bulk material as well known to a person skilled in the art.

A “non-optical surface of a mold half” refers to mold half surface whichdoes not contact the lens forming material during cast molding of acontact lens.

The invention is generally related to a contact lens manufacturingmethod for cast-molding of silicone hydrogel contact lenses havingenhanced oxygen permeability without adversely affecting desirable lensmechanical properties (e.g., modulus). The invention is partly based onthe discovery that when a small amount of a radical scavenger can beadded in a SiHy lens formulation (i.e., a polymerizable composition forcast-molding of SiHy contact lenses), the resultant SiHy lensformulation can have a bi-phase curing profile as determined by usingthermal DSC (Differential scanning calorimetry) to determine the curing(polymerization) kinetics of the polymerizable composition at a curingtemperature of from about 45° C. to about 100° C. as function of time.With such a bi-phase curing profile, the SiHy lens formulation can bethermally cured at the curing temperature to form a SiHy contact lenshaving an oxygen permeability higher than that for a SiHy lensformulation having the substantially identical composition exceptingbeing free of any radical scavenger. This method of the invention can beeasily implemented in the production of SiHy contact lenses having adesired oxygen permeability from a SiHy lens formulation with aminimized amount of silicone-containing polymerizable components.

The present invention provides a method for producing silicone hydrogelcontact lenses, comprising the step of: (1) obtaining a polymerizablecomposition which is clear at room temperature, wherein thepolymerizable composition comprises (a) at least one siloxane-containingvinylic monomer, (b) at least one polysiloxane vinylic crosslinker, (c)from about 15% to about 55% (preferably from about 20% to about 50%,more preferably from about 25% to about 45%) by weight of at least onehydrophilic (meth)acrylamido monomer having 3 to 8 carbon atoms, (d)from 0 to about 25% (preferably 1% to about 20%, more preferably fromabout 2% to about 15%, even more preferably from about 3% to about 10%)by weight of an organic solvent having 2 to 8 carbon atoms relative tothe total weight of the polymerizable composition, (e) at least onethermal free radical initiator, and (f) at least one radical scavengerpresent in an amount (preferably at least about 100 ppm, more preferablyat least about 200 ppm, even more preferably at least about 300 ppm,relative to the total weight of the polymerizable composition) forproviding the polymerizable composition with a bi-phase curing profiledetermined by using thermal DSC to polymerization kinetics of thepolymerizable composition at a curing temperature of from about 45° C.to about 100° C. as function of time; (2) introducing the polymerizablecomposition into a lens mold, wherein the lens mold comprises a malemold half having a first molding surface and a female mold half having asecond molding surface, wherein the male and female mold halves areconfigured to receive each other such that a mold cavity is formedbetween the first and second molding surfaces when the mold is closed;(3) curing thermally the polymerizable composition in the lens mold inan oven at the curing temperatures for at least 30 minutes (preferablyat least about 40 minutes, more preferably at least about 50 minutes,even more preferably at least about 60 minutes) to form an unprocessedsilicone hydrogel lens contact lens; (4) separating the lens mold intothe male and female mold halves, with the unprocessed silicone hydrogelcontact lens being adhered on a lens-adhered mold half which is one ofthe male and female mold halves; and (5) removing the unprocessedsilicone hydrogel contact lens from the lens-adhered mold half.

In a preferred embodiment, step (5) (i.e., the step of removing) ispreferably performed, before the unprocessed silicone hydrogel contactlens is contact with water or any liquid, by (a) bring a ultrasonic hornin direct contact with at least one area of a non-optical surface of thelens-adhered mold half having the unprocessed silicone hydrogel lensprecursor attached thereon and (b) applying a ultrasonic vibrationalenergy of from about 0.2 to about 18 J to the at least one area of thenon-optical surface of the lens-adhered mold half having the unprocessedsilicone hydrogel contact lens adhered thereon so as to remove theunprocessed silicone hydrogel contact lens from the lens-adhered moldhalf. More preferably, the method further comprises a step of (i.e.,step (6)): subjecting the unprocessed silicone hydrogel contact lens toone or more post-molding processes selected from the group consisting ofextraction, hydration, surface treatment, packaging, sterilization, andcombinations thereof.

In a preferred embodiment, the sum of the amounts of components (a) to(d) is at least about 90% (preferably at least about 93%, morepreferably at least about 95%, even more preferably at least about 98%)by weight relative to the total weight of the polymerizable composition.

In accordance with the invention, a siloxane-containing vinylic monomercan be any vinylic monomer of formula (M1) or (M2)

in which: a1 is zero or 1; R_(o) is H or methyl; X_(o) is O or NR₁; L₁is a C₂-C₈ alkylene divalent radical or a divalent radical of

alkylene divalent radical which has zero or one hydroxyl group; L₁″ isC₃-C₈ alkylene divalent radical which has zero or one hydroxyl group; X₁is O, NR₁, NHCOO, OCONH, CONR₁, or NR₁CO; R₁ is H or a C₁-C₄ alkylhaving 0 to 2 hydroxyl group; R_(t1) and R_(t2) independent of eachother are a C₁-C₄ alkyl; X₁′ is O or NR₁; q1 is an integer of 1 to 20;q2 is an integer of 0 to 20; n1 is an integer of 3 to 25; and r1 is aninteger of 2 or 3.

Examples of preferred siloxane-containing vinylic monomers of formula(M1) include without limitation α-(meth)acryloxypropyl terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-(meth)acryloxy-2-hydroxypropyloxypropyl terminated ω-C₁-C₄-alkylterminated polydimethylsiloxane,α-(2-hydroxyl-methacryloxypropyloxypropyl)-ω-C₁-C₄-alkyl-decamethylpentasiloxane,α-[3-(meth)acryloxyethoxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxy-propyloxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxyisopropyloxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxybutyloxy-2-hydroxypropyloxypropyl]-terminatedω—C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxyethylamino-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxypropylamino-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxy-butylamino-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[(meth)acryloxy(polyethylenoxy)-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[(meth)acryloxy-2-hydroxypropyloxy-ethoxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[(meth)acryloxy-2-hydroxypropyl-N-ethylaminopropyl]-terminatedω—C₁-C₄-alkyl terminated polydimethylsiloxane,α-[(meth)acryloxy-2-hydroxypropyl-aminopropyl]-terminated ω-C₁-C₄-alkylterminated polydimethylsiloxane,α-[(meth)acryloxy-2-hydroxypropyloxy-(polyethylenoxy)propyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-(meth)acryloylamidopropyloxypropyl terminated ω-C₁-C₄-alkyl terminatedpolydimethylsiloxane, α-N-methyl-(meth)acryloylamidopropyloxypropylterminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acrylamidoethoxy-2-hydroxypropyloxy-propyl]-terminatedω-C₁-C₄-alkyl polydimethylsiloxane,α-[3-(meth)acrylamidopropyloxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acrylamidoisopropyloxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acrylamidobutyloxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloylamido-2-hydroxypropyloxypropyl] terminatedω-C₁-C₄-alkyl polydimethylsiloxane,α-[3-[N-methyl-(meth)acryloylamido]-2-hydroxypropyloxypropyl]terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,N-methyl-N′-(propyltetra(dimethylsiloxy)dimethylbutylsilane)(meth)acrylamide,N-(2,3-dihydroxypropane)-N′-(propyltetra(dimethylsiloxy)dimethylbutylsilane)(meth)acrylamide,(meth)acryloylamidopropyltetra(dimethylsiloxy)dimethylbutylsilane,α-vinyl carbonate-terminated ω-C₁-C₄-alkyl-terminatedpolydimethylsiloxanes, α-vinyl carbamate-terminatedω—C₁-C₄-alkyl-terminated polydimethylsiloxane, those disclosed in U.S.Pat. Nos. 9,097,840 and 9,103,965, and mixtures thereof. The abovepreferred polysiloxanes vinylic monomers of formula (M1) can be obtainedfrom commercial suppliers (e.g., Shin-Etsu, Gelest, etc.) or preparedaccording to procedures described in patents, e.g., U.S. Pat. Nos.5,070,215, 6,166,236, 6,867,245, 8,415,405, 8,475,529, 8,614,261, and9,217,813, or by reacting a hydroxyalkyl (meth)acrylate or(meth)acrylamide or a (meth)acryloxypolyethylene glycol with amono-epoxypropyloxypropyl-terminated polydimethylsiloxane, by reactingglycidyl (meth)acrylate with a mono-carbinol-terminatedpolydimethylsiloxane, a mono-aminopropyl-terminatedpolydimethylsiloxane, or a mono-ethylaminopropyl-terminatedpolydimethylsiloxane, or by reacting isocyanatoethyl (meth)acrylate witha mono-carbinol-terminated polydimethylsiloxane according to couplingreactions well known to a person skilled in the art.

Examples of preferred siloxane-containing vinylic monomers of formula(M2) include without limitation tris(trimethylsilyloxy)silylpropyl(meth)acrylate,[3-(meth)acryloxy-2-hydroxypropyloxy]propylbis(trimethylsiloxy)methylsilane,[3-(meth)acryloxy-2-hydroxypropyloxy]propylbis(trimethylsiloxy)butylsilane,3-(meth)acryloxy-2-(2-hydroxyethoxy)-propyloxy)propylbis(trimethylsiloxy)methylsilane, 3-(meth)acryloxy-2-hydroxypropyloxy)propyltris(trimethylsiloxy)silane,N-[tris(trimethylsiloxy)silylpropyl]-(meth)acrylamide,N-(2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)propyloxy)propyl)-2-methyl(meth)acrylamide,N-(2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)propyloxy)-propyl)(meth)acrylamide,N-(2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)propyloxy)propyl)-2-methylacrylamide,N-(2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)propyloxy)propyl)(meth)acrylamide,N-[tris(dimethylpropylsiloxy)silylpropyl]-(meth)acrylamide,N-[tris(dimethylphenylsiloxy)silylpropyl] (meth)acrylamide,N-[tris(dimethylethylsiloxy)silylpropyl](meth)acrylamide, N,N-bis[2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)propyloxy)propyl]-2-methyl(meth)acrylamide,N,N-bis[2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)-propyloxy)propyl](meth)acrylamide,N,N-bis[2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)-propyloxy)propyl]-2-methyl(meth)acrylamide, N,N-bis[2-hydroxy-3-(3-(tris(trimethylsilyloxy)-silyl)propyloxy)propyl] (meth)acrylamide,N-[2-hydroxy-3-(3-(t-butyldimethylsilyl)propyloxy)-propyl]-2-methyl(meth)acrylamide,N-[2-hydroxy-3-(3-(t-butyldimethylsilyl)propyloxy)propyl](meth)acrylamide,N, N-bis[2-hydroxy-3-(3-(t-butyldimethylsilyl)propyloxy)propyl]-2-methyl(meth)acrylamide,N-2-(meth)acryloxyethyl-O-(methyl-bis-trimethylsiloxy-3-propyl)silylcarbamate, 3-(trimethylsilyl)propylvinyl carbonate,3-(vinyloxycarbonylthio)propyl-tris(trimethyl-siloxy)silane,3-[tris(trimethylsiloxy)silyl]propylvinyl carbamate,3-[tris(trimethylsiloxy)silyl] propyl allyl carbamate,3-[tris(trimethylsiloxy)silyl]propyl vinyl carbonate, those disclosed inU.S. Pat. Nos. 9,097,840, 9,103,965 and 9,475,827, and mixtures thereof.The above preferred siloxane-containing vinylic monomers can be obtainedfrom commercial suppliers or can be prepared according to proceduresdescribed in U.S. Pat. Nos. 5,070,215, 6,166,236, 7,214,809, 8,475,529,8,658,748, 9,097,840, 9,103,965, and 9,475,827.

Any suitable polysiloxane vinylic crosslinkers can be used in theinvention. Examples of preferred polysiloxane vinylic crosslinkers aredi-(meth)acryloyl-terminated polydimethylsiloxanes; di-vinylcarbonate-terminated polydimethylsiloxanes; di-vinylcarbamate-terminated polydimethylsiloxane;N,N,N′,N′-tetrakis(3-methacryloxy-2-hydroxypropyl)-alpha,omega-bis-3-aminopropyl-polydimethylsiloxane;polysiloxane-containing macromer selected from the group consisting ofMacromer A, Macromer B, Macromer C, and Macromer D described in U.S.Pat. No. 5,760,100; polysiloxane-containing macromers disclosed in U.S.Pat. Nos. 4,136,250, 4,153,641, 4,182,822, 4,189,546, 4,343,927,4,254,248, 4,355,147, 4,276,402, 4,327,203, 4,341,889, 4,486,577,4,543,398, 4,605,712, 4,661,575, 4,684,538, 4,703,097, 4,833,218,4,837,289, 4,954,586, 4,954,587, 5,010,141, 5,034,461, 5,070,170,5,079,319, 5,039,761, 5,346,946, 5,358,995, 5,387,632, 5,416,132,5,451,617, 5,486,579, 5,962,548, 5,981,675, 6,039,913, 6,762,264,4,259,467, 4,260,725, and 4,261,875.

One class of preferred polysiloxane vinylic crosslinkers aredi-(meth)acryloyloxy-terminated polysiloxane vinylic crosslinkers eachhaving dimethylsiloxane units and hydrophilized siloxane units eachhaving one methyl substituent and one monovalent C₄-C₄₀ organic radicalsubstituent having 2 to 6 hydroxyl groups as disclosed in U.S. Pat. App.Pub. No. 2017-0166673 A1, more preferably a polysiloxane vinyliccrosslinker of formula (I)

in which:

ν1 is an integer of from 30 to 500 and 031 is an integer of from 1 to75, provided that ω1/ν1 is from about 0.035 to about 0.15 (preferablyfrom about 0.040 to about 0.12, even more preferably from about 0.045 toabout 0.10);

X₀₁ is O or NR_(N) in which R_(N) is hydrogen or C₁-C₁₀-alkyl;

R₀ is hydrogen or methyl;

R_(I1) and R_(I2) independently of each other are a substituted orunsubstituted C₁-C₁₀ alkylene divalent radical or a divalent radical of—R_(I4)—O—R_(I5)— in which R_(I4) and R_(I5) independently of each otherare a substituted or unsubstituted C₁-C₁₀ alkylene divalent radical;

R_(I3) is a monovalent radical of any one of formula (Ia) to (Ie)

-   -   p1 is zero or 1; m1 is an integer of 2 to 4; m2 is an integer of        1 to 5; m3 is an integer of 3 to 6; m4 is an integer of 2 to 5;

R_(I6) is hydrogen or methyl;

R₁₇ is a C₂-C₆ hydrocarbon radical having (m2+1) valencies;

R₁₈ is a C₂-C₆ hydrocarbon radical having (m4+1) valencies;

R₁₉ is ethyl or hydroxymethyl;

R_(I10) is methyl or hydroxymethyl;

R_(I11) is hydroxyl or methoxy;

X_(I1) is a sulfur linkage of —S— or a teriary amino linkage of—NR_(I12)— in which R_(I12) is C₁-C₁ alkyl, hydroxyethyl, hydroxypropyl,or 2,3-dihydroxypropyl; and

X₁₂ is an amide linkage of

in which R_(I13) is hydrogen or C₁-C₁₀ alkyl.

In a particularly preferred embodiment, the monovalent radical R_(I3) isa radical of formula (Ie) in which m1 is 3, p1 is 1, and R_(I6) ishydrogen. Such a preferred polysiloxane vinylic crosslinker isrepresented by formula (A)

in which ν1 and ω1 are as defined above.

A polysiloxane vinylic crosslinker of formula (I) can be preparedaccording to procedures described in U.S. Pat. Appl. Pub. No.2017-0166673 A1.

Other classes of preferred polysiloxane vinylic crosslinkers are vinyliccrosslinkers of any one of formula (1) to (7)

in which:

-   -   ν1 is an integer of from 30 to 500;    -   ν2 is an integer of from 5 to 50;    -   ν3 is an integer of from 5 to 100;    -   ω2 and ω3 independent of each other are an integer of from 1 to        15;    -   a1 and g1 independent of each other is zero or 1;    -   h1 is an integer of 1 to 20 and h2 is an integer of 0 to 20;    -   m1 and m3 independent of each other is 0 or 1, m2 is an integer        of 1 to 6, m4 is an integer of 1 to 5, m5 is 2 or 3;    -   q1 is an integer of 1 to 20, q2 is an integer of 0 to 20, q3 is        an integer of 0 to 2, q4 is an integer of 2 to 50, q5 and q6        independent of each other are a number of 0 to 35, provided that        (q4+q5+q6) is an integer of 2 to 50;    -   x+y is an integer of from 10 to 30;    -   e1 is an integer of 5 to 100, p1 and b1 independent of each        other are an integer of 0 to 50, provided that (e1+p1+b1)≥10 and        e1/(p1+b1)≥2 (preferably from about 2:1 to about 10:1, more        preferably from about 3:1 to about 6:1) when (p1+b1)≥1;    -   R₀ is H or methyl;    -   R₁, R_(1n), R_(2n), R_(3n), and R_(4n) independent of one        another are H or a C₁-C₄ alkyl having 0 to 2 hydroxyl group;    -   R_(n5) is H or a C₁-C₁₀ alkyl;    -   R₂ is a C₄-C₁₄ hydrocarbon divalent radical;    -   R₃ is a C₂-C₆ alkylene divalent radical;    -   R₄ and R₅ independent of each other are a C₁-C₆ alkylene        divalent radical or a C₁-C₆ alkylene-oxy-C₁-C₆ alkylene divalent        radical;    -   R₆ and R₇ independent of each other are a C₁-C₆ alkylene        divalent radical or a C₁-C₆ alkoxy-C₁-C₆ alkylene divalent        radical;    -   R₈ and R₉ independent of each other are a substituted or        unsubstituted C₁-C₁₂ alkylene divalent radical;    -   X_(o), X₁′, X_(o1), X_(o2), and X_(o3) independent of one        another are O or NR₁;    -   X₁ is O, NR₁, NHCOO, OCONH, CONR₁, or NR₁CO;    -   X_(o4) is —COO— or —CONR_(n5)—;    -   X_(o5) and X_(o7) independent of each other are a direct bond,        —COO— or —CONR_(n5)—;    -   X_(o6) is a direct bond, a C₁-C₆ alkylene divalent radical, a        C₁-C₆ alkylenoxy divalent radical, —COO—, or —CONR_(n5)—;    -   X_(o8) is a direct bond or —COO—;    -   X_(o9) is O or NR_(n5);    -   X₁₀ is a direct bond, a C₁-C₆ alkylene divalent radical, —COO—,        or —CONR_(n5)—;    -   E₁′ is a monovalent radical of

-   -   E₂ is a monovalent radical of

-   -   E₃ is a monovalent radical of

-   -   E₄ is a monovalent radical of

-   -   L₁ is a C₂-C₈ alkylene divalent radical or a divalent radical of        -L₁′-X₁-L₁″-,

-   -   L₁′ is a C₂-C₈ alkylene divalent radical which has zero or one        hydroxyl group;    -   L₁″ is C₃-C₈ alkylene divalent radical which has zero or one        hydroxyl group;    -   L₃ is a divalent radical of

in which PE is a divalent radical of or

-   -   L₃′ is C₃-C₈ alkylene divalent radical;    -   L₄ is a divalent radical of

-   -   hpL₁ is a divalent radical of

-   -   hpL₂ is a divalent radical of

-   -   hpL₃ is a divalent radical of

-   -   hpL₄ is a divalent radical of

-   -   pOAlk is a divalent radical of

in which EO is an oxyethylene unit (—CH₂CH₂—), PO is an oxypropyleneunit

and BO is an oxybutylene unit

-   -   M₀ is C₃-C₈ alkylene divalent radical;    -   M₁ is a C₄-C₁₄ hydrocarbon divalent radical;    -   M₂ and M₃ independent of each other are a C₁-C₆ alkylene        divalent radical;    -   J₀ is a C₁-C₁₂ hydrocarbon radical having 0 to 2 hydroxyl or        carboxyl groups;    -   G1 is a direct bond, a C₁-C₄ alkylene divalent radical, or a        bivalent radical of

in which M₀ is linked to Si atom while X₀₄ to X₁₀ are linked to thegroup of —CH₂— in formula (7) and at least one of Jo and G1 in formula(7) comprises at least one moieties selected from the group consistingof hydroxyl groups, urethane linkage of —OCONH—, amino groups of —NHR⁰,amino linkages of —NH—, amide linkages of —CONH—, carboxyl groups, andcombinations thereof;

-   -   G₂ is a C₁-C₄ alkylene divalent radical or a bivalent radical of

-   -   G₃ is a divalent radical of

in which

-   -   h3 and h4 independent of each other are 1 or 0;    -   G4 is a divalent radical of any one of (a) —NR₃′— in which R₃′        is hydrogen or C₁-C₃ alkyl,

in which G₅ is a C₁-C₆ alkylene divalent radical, 2-hydroxylpropylenedivalent radical, 2-(phosphonyloxy)propylene divalent radical,1,2-dihydroxyethylene divalent radical, 2,3-dihydroxybutylene divalentradical, and (d) —O-G₆-O— in which G₆ is a C₁-C₆ alkylene divalentradical, a divalent radical of

in which h4′ is 1 or 2, a divalent radical of

a divalent radical of

in which h5 is an integer of 1 to 5, a divalent radical of

in which h6 is 2 or 3, or a substituted C₃-C₈ alkylene divalent radicalhaving a hydroxyl group or phosphonyloxy group;

-   -   Y₁ is a C₁-C₆ alkylene divalent radical, 2-hydroxylpropylene        divalent radical, 2-(phosphonyloxy)propylene divalent radical,        1,2-dihydroxyethylene divalent radical, a divalent radical of

or a divalent radical of

-   -   Y₂ is a divalent radical of

-   -   Y₃ is a divalent radical of

-   -   Z₀ is a direct bond or a C₁-C₁₂ alkylene divalent radical;    -   Z₁ is a C₁-C₆ alkylene divalent radical, a hydroxyl- or        methoxy-substituted C₁-C₆ alkylene divalent radical, or a        substituted or unsubstituted phenylene divalent radical,    -   Z₂ is a C₁-C₆ alkylene divalent radical, a hydroxyl- or        methoxy-substituted C₁-C₆ alkylene divalent radical, a        dihydroxyl- or dimethoxy-substituted C₂-C₆ alkylene divalent        radical, a divalent radical of —C₂H₄—(O—C₂H₄)_(m2)—, a divalent        radical of —Z₄—S—S—Z₄—, a hydroxyl- or methoxy-substituted C₁-C₆        alkylene divalent radical, or a substituted or unsubstituted        phenylene divalent radical,    -   Z₃ is a divalent radical of any one of (a) —NR_(n3)—, (b)

(c) —NR₀—Z₅—NR₀—, and (d) —O—Z₆—O—,

-   -   Z₄ is a C₁-C₆ alkylene divalent radical,    -   Z₅ is a C₁-C₆ alkylene divalent radical, 2-hydroxylpropylene        divalent radical, 2-(phosphonyloxy)propylene divalent radical,        1,2-dihydroxyethylene divalent radical, 2,3-dihydroxybutylene        divalent radical,    -   Z₆ is (a) a C₁-C₆ alkylene divalent radical, (b) a divalent        radical of

or (c) a substituted C₃-C₈ alkylene divalent radical having a hydroxylgroup or phosphonyloxy group,

-   -   Z₇ is a divalent radical of

and

-   -   Z₈ is a divalent radical of

Polysiloxane vinylic crosslinkers of formula (1) can be obtained fromcommercial suppliers, or prepared by reacting glycidyl (meth)acrylate(meth)acryloyl chloride with a di-amino-terminated polydimethylsiloxaneor a di-hydroxyl-terminated polydimethylsiloxane, reactingisocyantoethyl (meth)acrylate with di-hydroxyl-terminatedpolydimethylsiloxanes, reacting an amino-containing acrylic monomer withdi-carboxyl-terminated polydimethylsiloxane in the presence of acoupling agent (a carbodiimide); reacting a carboxyl-containing acrylicmonomer with di-amino-terminated polydimethylsiloxane in the presence ofa coupling agent (a carbodiimide). Or reacting a hydroxyl-containingacrylic monomer with a di-hydroxy-terminated polydisiloxane.

Preferred examples of polysiloxane vinylic crosslinkers of formula (1)include without limitation α,ω-bis[3-(meth)acrylamidopropyl]-terminatedpolydimethylsiloxane, α,ω-bis[3-(meth)acryloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxyethoxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxypropyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxy-isopropyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxybutyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamidoethoxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamidopropyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamidoisopropyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamidobutyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxyethylamino-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxypropylamino-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxybutylamino-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acrylamidoethylamino-2-hydroxypropyloxy-propyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamidopropylamino-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamide-butylamino-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acryloxy-2-hydroxypropyloxy-ethoxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acryloxy-2-hydroxypropyl-N-ethylaminopropyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acryloxy-2-hydroxypropyl-aminopropyl]-polydimethylsiloxane,α,ω-bis[(meth)acryloxy-2-hydroxypropyloxy-(polyethylenoxy)propyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acryloxyethylamino-carbonyloxy-ethoxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acryloxyethylamino-carbonyloxy-(polyethylenoxy)propyl]-terminated polydimethylsiloxane, combinations thereof.

Chain-extended polysiloxane vinylic crosslinkers of formula (2) can beprepared according to the procedures described in U.S. Pat. Nos.5,034,461, 5,416,132, 5,449,729, 5,760,100, 7,423,074, and 8,529,057.Chain-extended polysiloxane vinylic crosslinkers of formula (3), (4) or(5) can be prepared according to the procedures described in detail inU.S. Pat. App. Pub. No. 2018-0100053 A1. Chain-extended polysiloxanevinylic crosslinkers of formula (6) can be prepared according to theprocedures described in detail in U.S. Pat. App. Pub. No. 2018-0100038A1. Chain-extended polysiloxane vinylic crosslinkers of formula (6) canbe prepared according to the procedures described in U.S. Pat. No.8,993,651.

Another class of preferred chain-extended polysiloxane vinyliccrosslinkers are those which each comprise at least two polysiloxanesegments and dangling hydrophilic polymer chains each covalentlyattached to a divalent radical separating each pair of adjacentpolysiloxane segments and having at least two pendant hydrophilic groupsand/or chains as disclosed in U.S. Pat. Appl. Pub. No. 2012-0088843 A1;those which each comprise at least two polysiloxane segments anddangling hydrophilic polymer chains each covalently attached to adivalent radical separating each pair of adjacent polysiloxane segmentsas disclosed in U.S. Pat. Appl. Pub. No. 2012-0088844 A1.

Examples of preferred hydrophilic (meth)acrylamido monomers includewithout limitation (meth)acrylamide, N-methyl (meth)acrylamide,N,N-dimethyl (meth)acrylamide, N-ethyl (meth)acrylamide, N,N-diethyl(meth)acrylamide, N-propyl (meth)acrylamide, N-isopropylacrylamide,N-3-methoxypropyl (meth)acrylamide, N-tert-butylacrylamide,N-2-hydroxyethyl (meth)acrylamide, N,N-bis(2-hydroxyethyl)(meth)acrylamide, N-2-hydroxypropyl (meth)acrylamide, N-3-hydroxypropyl(meth)acrylamide, N-2,3-dihydroxypropyl (meth)acrylamide,N-[tris(hydroxymethyl)methyl]-acrylamide, N-2-aminoethyl(meth)acrylamide, N-2-methylaminoethyl (meth)acrylamide,N-2-ethylaminoethyl (meth)acrylamide, N-2-dimethylaminoethyl(meth)acrylamide, N-3-aminopropyl (meth)acrylamide,N-3-methylaminopropyl (meth)acrylamide, N-3-dimethylaminopropylacrylamide, 2-(meth)acrylamidoglycolic acid, and combinations thereof.It is believed that such hydrophilic (meth)acrylamido monomers can beused in increasing the glass transition temperature of a resultantsilicone hydrogel material.

Examples of preferred organic solvents having 2 to 8 carbon atomsinclude without limitation, alcohols having 2 to 8 carbon atoms (e.g.,ethanol, 1-propanol, isopropanol, 1-butanol, sec-butanol, isobutanol,tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol,3-methyl-2-butanol, 2-methyl-1-butanol, 2,2-dimethyl-1-propanol,tert-amyl alcohol, 2-hexanol, 3-hexanol, 2-heptanol, 2-octanol,2-nonanol, 2-decanol, 3-octanol, 2-methyl-2-pentanol,2,3-dimethyl-2-butanol, 3-methyl-3-pentanol, 2-methyl-2-hexanol,3-methyl-3-hexanol, 3-methyl-3-heptanol, 4-methyl-4-heptanol,2-methyl-2-heptanol, 3-ethyl-3-hexanol, 3-methyl-3-heptanol,2,4-dimethyl-2-pentanol, 3-ethyl-3-pentanol, 1-methoxy-2-propanol,3-ethoxy-1-propanol, 1-ethoxy-2-propanol, 1-isobutoxy-2-propanol,3-methoxy-1-butanol, 1-methoxy-2-butanol, norborneol,1-methylcyclohexanol, 1-methylcyclopentanol, 1-ethylcyclopentanol,1-ethylcyclopentanol, 4-hydroxy-4-methyl-1-cyclopentanol, orcombinations thereof), dipropylene glycol methyl ether, ethylene glycoln-butyl ether, acetone, methyl ethyl ketone, diethylene glycol n-butylether, diethylene glycol methyl ether, propylene glycol methyl ether,propylene glycol methyl ether acetate, propylene glycol n-propyl ether,propylene glycol n-butyl ether, ethyl acetate, butyl acetate, amylacetate, methyl lactate, ethyl lactate, propyl lactate,1-methyl-2-pyrrolidone, N,N-dimethylpropionamide, dimethyl formamide,dimethyl acetamide, dimethyl propionamide, N-methyl pyrrolidinone, andmixtures thereof. Preferably, the organic solvent is an alcohol having 3to 5 carbon atoms (e.g., 1-propanol, isopropanol, 1-butanol,sec-butanol, isobutanol, tert-butyl alcohol, 1-pentanol, 2-pentanol,3-pentanol, 3-methyl-2-butanol, 2-methyl-1-butanol,2,2-dimethyl-1-propanol, tert-amyl alcohol, 1-methoxy-2-propanol,3-ethoxy-1-propanol, 1-ethoxy-2-propanol, or combinations thereof).

In a preferred embodiment, an organic solvent having 2 to 6 carbon atomsand a boiling point of lower than 105° C. is be used in the invention.Examples of preferred organic solvents include without limitation,alcohols having 2 to 5 carbon atoms (e.g., ethanol, 1-propanol,isopropanol, sec-butanol, tert-butyl alcohol, tert-amyl alcohol,acetone, methyl ethyl ketone, ethyl acetate, and mixtures thereof.Preferably, the organic solvent is an alcohol having 2 to 5 carbon atoms(e.g., ethanol, 1-propanol, isopropanol, sec-butanol, tert-butylalcohol, tert-amyl alcohol, or combinations thereof). With a boilingpoint below 105° C., such an organic solvent could be evaporated to someextend at the post-curing heating step at a post-curing temperaturehigher than 105° C.

In accordance with the present invention, any radical scavenger can beused as long as it can be dissolved in a fluid composition to be used.Examples of radical scavengers include, but are not limited to, N-oxylor nitroxide compounds, quinone methides, nitroso compounds,phenothiazine, phenols, and naturally-occurring antioxidant free-radicalscavengers. Examples of naturally-occurring antioxidant free-radicalscavengers include without limitation vitamin C (ascorbic acid), VitaminE and citric acid. Preferably, the radical scavenger is TEMPO(4-hydroxy-2,2,6,6,-tetramethyl-1-piperidinyloxy, free radical)(CAS#2226-96-2).

In accordance with the invention, a polymerizable composition of theinvention can further comprise about 10% (preferably about 8%, morepreferably about 6%, even more preferably about 4%) by weight or less ofone or more polymerizable components selected from the group consistingof an N-vinyl amide monomer, a hydrophilic (meth)acryloxy monomer, ahydrophobic acrylic monomer capable of forming a homopolymer with a T,of at least about 60° C. (preferably at least about 70° C., morepreferably at least about 80° C., even more preferably at least about90° C.), a non-silicone vinylic crosslinker, and combinations thereof,relative to the total weight of the polymerizable composition.

Any suitable N-vinyl amide monomers can be used in the invention.Examples of preferred N-vinyl amide monomers include without limitationN-vinylpyrrolidone, N-vinyl piperidone, N-vinyl caprolactam,N-vinyl-N-methyl acetamide, N-vinyl formamide, N-vinyl acetamide,N-vinyl isopropylamide, N-vinyl-N-methyl acetamide, N-vinyl-N-ethylacetamide, N-vinyl-N-ethyl formamide, and mixtures thereof. Preferably,the N-vinyl amide monomer is N-vinylpyrrolidone, N-vinyl-N-methylacetamide, or combinations thereof.

Examples of preferred hydrophilic (meth)acryloxy monomers includeswithout limitation 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycerol methacrylate(GMA), di(ethylene glycol) (meth)acrylate, tri(ethylene glycol)(meth)acrylate, tetra(ethylene glycol) (meth)acrylate, poly(ethyleneglycol) (meth)acrylate having a number average molecular weight of up to1500, ethylene glycol methyl ether (meth)acrylate, di(ethylene glycol)methyl ether (meth)acrylate, tri(ethylene glycol) methyl ether(meth)acrylate, tetra(ethylene glycol) methyl ether (meth)acrylate,C₁-C₄-alkoxy poly(ethylene glycol) (meth)acrylate having a weightaverage molecular weight of up to 1500, (meth)acrylic acid, ethylacrylicacid, 2-aminoethyl (meth)acrylate, 2-methylaminoethyl (meth)acrylate,2-ethylaminoethyl (meth)acrylate, 3-aminopropyl (meth)acrylate,3-methylaminopropyl (meth)acrylate, 3-ethylaminopropyl (meth)acrylate,3-amino-2-hydroxypropyl (meth)acrylate, trimethylammonium 2-hydroxypropyl (meth)acrylate hydrochloride, dimethylaminoethyl (meth)acrylate,and combinations thereof.

Any hydrophobic acrylic monomer can be used in the invention as areactive diluent for solubilizing other polymerizable components in apolymerizable composition of the invention, provided that it can form ahomopolymer with a T, of at least about 60° C. It is believed that sucha hydrophobic acrylic monomer can increase a T, of the dominant phase ofa resultant silicone hydrogel material above the room temperature andmay make the unprocessed silicone hydrogel contact lens more rigid forhandling.

Examples of such hydrophobic acrylic monomers includes methylmethacrylate (T_(g)=105° C. of homopolymer), ethyl methacrylate(T_(g)=65° C. of homopolymer), isopropyl methacrylate (T_(g)=81° C. ofhomopolymer), sec-butyl methacrylate (T_(g)=60° C. of homopolymer),tert-butyl methacrylate (T_(g)=107° C. of homopolymer), cyclohexylmethacrylate (T_(g)=83° C. of homopolymer), isobornyl acrylate(T_(g)=94° C. of homopolymer), isobornyl methacrylate (T_(g)=110° C. ofhomopolymer), phenyl methacrylate (T_(g)=110° C. of homopolymer),4-tert-butylstyrene (T_(g)=132° C. of homopolymer), 2-methylstyrene(T_(g)=120° C. of homopolymer), styrene (T_(g)=100° C. of homopolymer),4-ethoxystyrene (T_(g)=86° C. of homopolymer), 2,4-dimethystyrene(T_(g)=112° C. of homopolymer), 2,5-dimethylstyrene (T_(g)=143° C. ofhomopolymer), 3,5-dimethylstyrene (T_(g)=104° C. of homopolymer), andcombinations thereof. More preferably, methyl methacrylate, tert-butylmethacrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornylmethacrylate, or a combination thereof is used in the invention. Evenmore preferably, methyl methacrylate, tert-butyl methacrylate,cyclohexyl methacrylate, or a combination thereof is used in theinvention.

Examples of preferred non-silicone vinylic cross-linking agents includewithout limitation ethyleneglycol di-(meth)acrylate, diethyleneglycoldi-(meth)acrylate, triethyleneglycol di-(meth)acrylate,tetraethyleneglycol di-(meth)acrylate, glycerol di-(meth)acrylate,1,3-propanediol di-(meth)acrylate, 1,3-butanediol di-(meth)acrylate,1,4-butanediol di-(meth)acrylate, glycerol 1,3-diglycerolatedi-(meth)acrylate, ethylenebis[oxy(2-hydroxypropane-1,3-diyl)]di-(meth)acrylate, bis[2-(meth)acryloxyethyl] phosphate,trimethylolpropane di-(meth)acrylate, and3,4-bis[(meth)acryloyl]tetrahydrofuan, diacrylamide (i.e.,N-(1-oxo-2-propenyl)-2-propenamide), dimethacrylamide (i.e.,N-(1-oxo-2-methyl-2-propenyl)-2-methyl-2-propenamide),N,N-di(meth)acryloyl-N-methylamine, N,N-di(meth)acryloyl-N-ethylamine,N,N′-methylene bis(meth)acrylamide, N,N′-ethylene bis(meth)acrylamide,N,N′-dihydroxyethylene bis(meth)acrylamide, N,N′-propylenebis(meth)acrylamide, N,N′-2-hydroxypropylene bis(meth)acrylamide,N,N′-2,3-dihydroxybutylene bis(meth)acrylamide,1,3-bis(meth)acrylamide-propane-2-yl dihydrogen phosphate (i.e.,N,N′-2-phophonyloxypropylene bis(meth)acrylamide), piperazinediacrylamide (or 1,4-bis(meth)acryloyl piperazine), tetraethyleneglycoldivinyl ether, triethyleneglycol divinyl ether, diethyleneglycol divinylether, ethyleneglycol divinyl ether, triallyl isocyanurate, triallylcyanurate, trimethylopropane trimethacrylate, pentaerythritoltetramethacrylate, bisphenol A dimethacrylate, and combinations thereof.A preferred non-silicone vinylic cross-linking agent istetra(ethyleneglycol) di-(meth)acrylate, tri(ethyleneglycol)di-(meth)acrylate, ethyleneglycol di-(meth)acrylate, di(ethyleneglycol)di-(meth)acrylate, tetraethyleneglycol divinyl ether, triethyleneglycoldivinyl ether, diethyleneglycol divinyl ether, ethyleneglycol divinylether, triallyl isocyanurate, triallyl cyanurate, or a combinationthereof. In accordance with the invention, the amount of a non-siliconevinylic crosslinker in a polymerizable composition of the invention isabout 1.5% or less (preferably about 1.2% or less, more preferably fromabout 0.1% to about 1.0%) by weight relative to the total weight of allpolymerizable components in the polymerizable composition.

Any suitable thermal polymerization initiators, known to the skilledartisan, can be used in the invention. Examples of thermalpolymerization initiators includes without limitation peroxides,hydroperoxides, azo-bis(alkyl- or cycloalkylnitriles), persulfates,percarbonates or mixtures thereof. Examples of thermal free radicalinitiators are benzoylperoxide, tert.-butyl peroxide,di-tert.-butyl-diperoxyphthalate, tert.-butyl hydroperoxide,azo-bis(isobutyronitrile) (AIBN), 1,1-azodiisobutyramidine, 1,1′-azo-bis(1-cyclohexanecarbonitrile), 2,2′-azo-bis(2,4-dimethylvaleronitrile) andthe like. The polymerization is carried out conveniently in anabove-mentioned solvent at elevated temperature, for example at atemperature of from 25 to 100° C. and preferably 40 to 80° C. Thereaction time may vary within wide limits, but is conveniently, forexample, from 1 to 24 hours or preferably from 2 to 12 hours. It isadvantageous to previously degas the components and solvents used in thepolymerization reaction and to carry out said copolymerization reactionunder an inert atmosphere, e.g., under N₂ or Ar atmosphere.

In accordance with a preferred embodiment of the invention, apolymerizable composition of the invention can further comprise (butpreferably comprises) one or more UV-absorbing vinylic monomers andoptionally (but preferably) one or more UV/HEVL-absorbing vinylicmonomers. The term “UV/HEVL-absorbing vinylic monomer” refers to avinylic monomer that can absorb UV light and high-energy-violet-light(i.e., light having wavelength between 380 nm and 440 nm. Examples ofUV-absorbing vinylic monomers and UV/HEVL-absorbing vinylic monomers areknown to a person skilled in the art and are disclosed in the patentsand patent application publications, e.g., U.S. Pat. No. 9,315,669, US2018-0081197 A1, etc.

A polymerizable composition of the invention can also comprise othernecessary components known to a person skilled in the art, such as, forexample, a visibility tinting agent (e.g., one or more polymerizabledyes, pigments, or mixtures thereof), antimicrobial agents (e.g.,preferably silver nanoparticles), a bioactive agent, leachablelubricants, leachable tear-stabilizing agents, mold releasing agent, andmixtures thereof, as known to a person skilled in the art.

A polymerizable composition of the invention can be prepared by blendingall of the desirable components according to any known techniques.

Methods of manufacturing mold sections for cast molding a contact lensare generally well known to those of ordinary skill in the art. Theprocess of the present invention is not limited to any particular methodof forming a mold. In fact, any method of forming a mold can be used inthe present invention. However, for illustrative purposes, the followingdiscussion has been provided as one embodiment of forming a mold.

In general, a mold comprises at least two mold halves (or moldsections), one male half and one female mold half. The male mold halfhas a first molding (or optical) surface which is in direct contact witha polymerizable composition for cast molding of a contact lens anddefines the posterior (concave) surface of a molded contact lens; andthe female mold half has a second molding (or optical) surface which isin direct contact with the polymerizable composition and defines theanterior (convex) surface of the molded contact lens. The male andfemale mold halves are configured to receive each other such that alens-forming cavity is formed between the first molding surface and thesecond molding surface.

FIG. 1 schematically illustrates a preferred mold 100 used in themethods of the invention. The mold 100 comprises a female mold half 1and male mold half 2.

The male mold half 2 comprises a base 61, a substantially cylindricalbody 25 which extends upward from base 61, a posterior molding surfacedefining the posterior (concave) surface of a molded contact lens, andan annular shoulder 65 which surrounds the posterior molding surface.The posterior molding surface protrudes outward from the top of body 25.The annular shoulder 65 shown is flat. It is understood that the annularshoulder 65 can have any suitable surface, such as, e.g., a tiltedsurface.

The female mold half 1 comprises a base 51, a substantially cylindricalbody 15 which extends upward from base 51, an anterior molding surfacedefining the anterior (convex) surface of a molded contact lens, and acollar 4. The anterior molding surface recesses downward from the top ofthe body 15. Collar 4 (or up-protruding flange) is preferably integralpart of the female mold half 1 and protrudes upward from the top of thebody 15. A circumferential groove (or recess) 11 is formed on top of thebody 15 between the anterior molding surface and functions as anoverflow for any excess unpolymerized lens-forming material.

The term “collar” as used herein refers to a peripheral circular partwhich protrudes upward from the top of body of one of the two matingmold halves. A collar can be attached to or preferably integral part ofthat mold half and which can encircle the other mold half to provide atight seal between the two mold halves. It is understood that the collarcan be provided on either of the male and female mold halves.

The female mold half 1 and a male mold half 2 are configured to receiveeach other such that a contact lens forming cavity 12 is formed betweenthe anterior and posterior molding surfaces. The collar 4 encircles thebody 25 of the male mold half 2 to provide a tight seal 5 between thefemale and male mold halves when the mold is closed. Typically, there isno lens material in the seal.

In operation, mold halves 1 and 2 can be first injection molded from aplastic resin in an injection molding apparatus, as well known to aperson skilled in the art. A specific amount of a polymerizablelens-forming material is typically dispensed into the female mold half 1by means of a dispensing device and then the male mold half 2 is put onand the mold 100 is closed (FIG. 1). As the mold 100 closes, any excessunpolymerized lens-forming material is pressed into an overflow 11provided on the female mold half 1. Subsequently, the polymerizablecomposition in the closed mold 100 is cured thermally in an oven oractinically with UV/visible irradiation.

The mold halves can be formed through various techniques, such asinjection molding. Methods of manufacturing mold halves for cast-moldinga contact lens are generally well known to those of ordinary skill inthe art. The process of the present invention is not limited to anyparticular method of forming a mold. In fact, any method of forming amold can be used in the present invention. The mold halves can be formedthrough various techniques, such as injection molding or lathing.Examples of suitable processes for forming the mold halves are disclosedin U.S. Pat. Nos. 4,444,711; 4,460,534; 5,843,346; and 5,894,002, whichare also incorporated herein by reference.

Virtually all materials known in the art for making molds can be used tomake molds for making contact lenses. For example, polymeric materials,such as polyethylene, polypropylene, polystyrene, PMMA, Topas® COC grade8007-S10 (clear amorphous copolymer of ethylene and norbornene, fromTicona GmbH of Frankfurt, Germany and Summit, N.J.), or the like can beused. Other materials that allow UV light transmission could be used,such as quartz glass and sapphire.

In accordance with the invention, the polymerizable composition can beintroduced (dispensed) into a cavity formed by a mold according to anyknown methods. A specific amount of a polymerizable lens-formingmaterial is typically dispensed into a female mold half by means of adispensing device and then a male mold half is put on and the mold isclosed. As the mold closes, any excess unpolymerized lens-formingmaterial is pressed into an overflow provided on the female mold half(or alternatively on the male mold half).

The closed mold containing the polymerizable composition subsequently iscured (i.e., polymerized) thermally in an oven to produce a moldedunprocessed silicone hydrogel lens precursor. Preferably, the oven withthe molds therein is purged with nitrogen by flowing nitrogen gasthrough the oven. It is understood that the thermal curing step can becarried out at one or more curing temperatures as known to personskilled in the art and illustrated in Examples.

After the polymerizable composition in the molds in the oven is cured toform unprocessed silicone hydrogel contact lenses, the temperature ofthe oven is increased to a post-curing temperature of about 1050° C. orhigher (preferably at least about 110° C., more preferably at leastabout 1150° C., even more preferably at least about 1200° C.), and theflow rate of nitrogen gas through the oven is increased to a second flowrate which is at least about 1.5 folds (preferably at least about 2.0folds, more preferably at least about 3.0 folds, even more preferably atleast about 4.0 folds) of the first flow rate.

The post-curing treatment step (i.e., step (5)) is carried out byheating the lens mold with the unprocessed silicone hydrogel contactlens therewithin in the oven at the post-curing temperature undernitrogen gas flow through the oven at the second flow rate for at leastabout 30 minutes (preferably at least about 60 minutes, more preferablyat least about 90 minutes, even more preferably at least about 120minutes).

After the post-curing treatment, the molds are removed from the oven.Subsequently, applying a force to non-optical surface of the female moldat a location about the center area of non-optical molding surface at anangle of less than about 30 degrees, preferably less than about 10degrees, most preferably less than about 5 degrees (i.e., in a directionsubstantially normal to center area of non-optical molding surface)relative to the axis of the mold to deform the female mold half whichbreaks the bonds between the optical molding surface of the female moldhalf and the molded lens, as shown in FIG. 2. Various ways of applying aforce to non-optical surface of the female mold half at a location aboutthe center area of non-optical molding surface along the axis of themold to deform the female mold half which breaks the bonds between theoptical molding surface of the female mold half and the molded lens. Itis understood that the mold-opening device can have any configurationsknown to a person skilled in the art for performing the function ofseparating two mold halves from each other. For example, referring toFIG. 2, the demolding assembly comprises a pin 70 positionable againstthe center area of non-optical molding surface of the female mold half.The pin 70 has a flat free end 70 a to enable a surface contact betweenthe free end 70 a and the center area of non-optical molding surface ofthe female mold half. It will be appreciated that the scope of theinvention is not limited to such a particular flat configuration of thepin end 70 a, for example the pin may have a rounded free end. In thepresent embodiment, the pin 70 is movable and the female mold halfremains stationary by applying a restraining force to the female moldhalf with a first prying finger 32 for maintaining the female mold halfin a fixed position. However, it is possible to arrange the assembly sothat the female mold half is movable and the pin 70 remains stationary,or so that both the pin 70 and the female mold half can be movedrelative to each other.

In use, during the demolding operation, the free end 70 a of the pin 70applies a longitudinally directed force to the central portion of thenon-optical surface of the female mold half. The first prying finger 32applies a counteractive force against the end face 51 a of the flange 51of the female mold half 1. Consequently, the female mold half iscompressed between the free end 70 a of the pin 70 and the first finger32. The compression force deforms the curved part of the female moldhalf and breaks the adhesive bond between the molding surface of thefemale mold half 1 and the anterior surface of the molded lens 12.

Then, apply a vertical lifting movement to the male mold half with asecond prying finger (while maintaining the restraints on the femalemold so as to effectuate gradual separation between the female mold andthe male mold.

After breaking the bond between the optical molding surface of thefemale mold half and the molded lens, the mold is separated, the moldedunprocessed contact lens adheres to the male mold half 2. It issurprising to find out that, according to the present invention, themolded contact lens adhering to the male mold half even though themolding surfaces of the female mold and male mold are not treated beforeor after dispensing a specific amount of a polymerizable lens-formingmaterial into one of the mold halves to render the molded contact lenspreferentially adhered to the female mold or male mold when separatingthe mold.

According to the present application as mentioned above, the lenstypically remains adhered to the male mold section. However, by usingsimilar principle, the compression can be applied to the applying aforce to non-optical surface of the male mold half at a location aboutthe center area of non-optical molding surface along the longitudinalaxis of the mold to deform the male mold half to compress the femalemold half between the pin and the first set of pry fingers so as tobreak the bonds between the optical molding surface of the male moldhalf and the molded lens, thereby the molded lens adheres to the femalemold half after separating the mold.

According to the present application, an ultrasonic welding system isused not to welding two pieces of plastic material together, but insteadto separate molded silicone hydrogel contact lens from the lens-adheredmold half. An ultrasonic welding system as illustrated in FIG. 3comprises: a power supply 300 which provides a high power AC signal withfrequency matching the resonance frequency of the ultrasonic stack. Anultrasonic stack composed of a converter 310, a booster 320 and a horn330. All three elements of the stack are specifically tuned to resonateat the same exact ultrasonic frequency (Typically 15, 20, 30, 35, 40 or70 kHz). The converts the electrical signal into a mechanical vibration.The booster modifies the amplitude of the vibration. The horn can alsodefine the amplitude of vibration and apply the mechanical vibration tothe parts to be contacted. However, any kind of mechanical system whichtransfers the vibrational energy from the converter to the mold half canbe used.

FIG. 4 illustrates an embodiment of the invention wherein an ultrasonichorn 330 having a flat surface 340 is sized to be approximately theouter diameter of the male mold half 2 and seated on extended flat edgesurround the outer concave surface 35 (or back surface of the annularshoulder 65 of the male mold half. The male mold half 2 proximate theultrasonic horn vibrates with the acoustical energy emitted from theultrasonic horn 330 while the contact lens 85 is attached thereon sothat a relative motion at the frequency of the acoustic energy takesplace between back surface of the annular shoulder 65 of the male moldhalf and the contact lens attached thereon. The male mold half and thecontact lens attached thereon is held stationary by a position holder75. A person skilled in the art knows which device can be used as aposition holder, for example, a level metal or a cup having an attachedlevel metal. The cup can be used to collect the lens separated from themale mold half. Furthermore, the cup can be attached a vacuum source andthe vacuum can assist the separation of the lens from the male moldhalf.

FIGS. 5A and 5B show an embodiment wherein an ultrasonic horn 330 havinga convex surface 340 is of a size that allows it to extend within theouter concave portion of male half mold half 2. The male mold half andthe contact lens 85 attached thereon is held stationary by a positionholder 75. FIG. 5A illustrates that the ultrasonic horn vibrates withthe acoustical energy emitted from the ultrasonic horn 330 while thecontact lens is attached thereon so that a relative motion at thefrequency of the acoustic energy takes place through contact surfacebetween inside of the outer concave portion of male half mold half 2 andthe contact lens attached thereon. FIG. 5B illustrates that theultrasonic horn vibrates with the acoustical energy emitted from theultrasonic horn 330 while the contact lens is attached thereon so that arelative motion at the frequency of the acoustic energy takes placethrough contact points between edges of the outer concave portion ofmale half mold half 2 and the contact lens attached thereon.

FIG. 6 illustrates an embodiment of the invention is shown wherein anultrasonic horn 330 having a flat surface 340 is sized to beapproximately the outer diameter of the female mold half 1 to contactthe center area of the outer convex portion of the female mold half. Thefemale mold half and the contact lens 85 attached thereon is heldstationary by a position holder 75. The center portion of back surface(non-optical surface) of the female mold half 1 proximate the ultrasonichorn vibrates with the acoustical energy emitted from the ultrasonichorn 330 while the contact lens is attached thereon so that a relativemotion at the frequency of the acoustic energy takes place between thefemale mold half and the contact lens attached thereon.

FIGS. 7A and 7B show an embodiment wherein an ultrasonic horn 330 havinga concave surface 340 is of a size that allows it to extend within theouter convex portion of female half mold half 1 to contact the centerarea of the outer convex portion of the female mold half. The femalemold half and the contact lens 85 attached thereon is held stationary bya position holder 75. FIG. 7A illustrates that the ultrasonic hornvibrates with the acoustical energy emitted from the ultrasonic horn 330while the contact lens is attached thereon so that a relative motion atthe frequency of the acoustic energy takes place through contact surfacebetween inside of the outer convex portion of female half mold half 1and the contact lens attached thereon. 7B illustrates that theultrasonic horn vibrates with the acoustical energy emitted from theultrasonic horn 330 while the contact lens is attached thereon so that arelative motion at the frequency of the acoustic energy takes placethrough contact points between edges of the outer concave portion offemale half mold half 1 and the contact lens attached thereon.

According to the present invention, the modification to the output partof the horn and the preferred parameters associated with operating thesystem are given in the following.

The ultrasonic welding system is comprised of a power supply 300 whichgenerates a frequency range from 15 kHz to 70 kHz by the use of solidstate power devices. This high frequency electrical energy is suppliedto a converter 320. This component changes the electrical energy intoultrasonic mechanical vibratory energy at the frequency of the convertedelectrical energy supply which is typically 15 kHz to 70 kHz. Thevibratory ultrasonic acoustical energy is then transmitted through anamplitude modifying device called a booster 320. The booster is apassive (i.e., non-powered) device which is used to modify the outputamplitude of the converter before it reaches the horn 330. The horn isshaped to have a flat surface, convex surface, a concave surface, or thelike 340 which is an acoustical tool that transfers the vibratory energydirectly to the non-optical surface of a mold half.

The present invention is practiced with the above described apparatus asfollows: an ultrasonic welding apparatus as described above, thespecific system being used for the investigation is a Dukane iQ SeriesES Servo Ultrasonic Welding Press System with a 30 kHz generator, 2:1booster. The generator creates a user settable, high voltage (˜1000Vrms), 30 kHz signal that is applied to the transducer. The transducerexpands and contract with this applied voltage and creates a mechanicalvibration at the face of the transducer. This vibration is amplified bythe booster and horn assembly. To maximize the effectiveness of themechanical vibration on the part, the vibration needs to be applied in aprescribed manner.

To operate the Dukane Servo system, the ultrasonic horn is lowered to apoint in space, where it begins to look for a reaction force equal tothe trigger force set by the user. It will continue to move downward atprescribed speed over a short distance looking for that reaction force.When that force is achieved, the system will fire the ultrasonics. Oncefired, the horn will seek to move to maintain that constant force. Forcemode was chosen to deal with the normal positional variation you wouldencounter with different parts placed slightly differently from theprevious part, as well as slight geometry variations from part to part.The generator output energy equals to the time integral of power.Example process settings are shown in the following table.

Process Parameter Setting Generator Frequency 30 or 40 kHz Booster 2:1Horn 2:1 Trigger Force 100 N Energy 0.1-40 J

According to the present invention, Generator Frequency is operatedbetween 15 kHz to 70 kHz, preferably between 20 kHz to 40 kHz, morepreferably between 30 kHz to 40 kHz. Trigger Force is operated between1.0 N to 150N, preferably between 20 N to 120N, more preferably between40 N to 110N, still more preferably between 80 N to 100N. Energy isoperated between 0.1 J to 40 J, preferably between 0.5 J to 30 J, stillmore preferably between 1.0 J to 20 J. The duration of applying theultrasonic vibration energy necessary to separate the molded hydrogelcontact lens from the female mold half or the male mold half attachedthereon is typically less than 10 seconds, preferably less than 5.0seconds, more preferably less than 2.0 seconds, still more preferablyless than 1.0 second.

Although various embodiments of the invention have been described usingspecific terms, devices, and methods, such description is forillustrative purposes only. The words used are words of descriptionrather than of limitation. It is to be understood that changes andvariations may be made by those skilled in the art without departingfrom the spirit or scope of the present invention, which is set forth inthe following claims. In addition, it should be understood that aspectsof the various embodiments may be interchanged either in whole or inpart or can be combined in any manner and/or used together, asillustrated below:

1. A method for producing silicone hydrogel contact lenses, comprisingthe steps of:

(1) obtaining a polymerizable composition which is clear at roomtemperature, wherein the polymerizable composition comprises (a) atleast one siloxane-containing vinylic monomer, (b) at least onepolysiloxane vinylic crosslinker, (c) from about 15% to about 55% byweight of at least one hydrophilic (meth)acrylamido monomer having 3 to8 carbon atoms, (d) from 0 to about 25% by weight of an organic solventhaving relative to the total weight of the polymerizable composition,wherein the organic solvent has 2 to 8 carbon atoms, (e) at least onethermal free radical initiator, and (f) at least one radical scavengerpresent in an amount for providing the polymerizable composition with abi-phase curing profile determined by using thermal DSC topolymerization kinetics of the polymerizable composition at a curingtemperature of from about 45° C. to about 100° C. as function of time;

(2) introducing the polymerizable composition into a lens mold, whereinthe lens mold comprises a male mold half having a first molding surfaceand a female mold half having a second molding surface, wherein the maleand female mold halves are configured to receive each other such that amold cavity is formed between the first and second molding surfaces whenthe mold is closed;

(3) curing thermally the polymerizable composition in the lens mold inan oven at the curing temperature for at least 30 minutes to form anunprocessed silicone hydrogel lens contact lens;

(4) separating the lens mold the male and female mold halves, with theunprocessed silicone hydrogel contact lens being adhered on alens-adhered mold half which is one of the male and female mold halves;and

(5) removing the unprocessed silicone hydrogel contact lens from thelens-adhered mold half.

2. The method of embodiment 1, wherein the polymerizable compositioncomprises from about 20% to about 50% by weight of at least onehydrophilic (meth)acrylamido monomer having 3 to 8 carbon atoms relativeto the total weight of the polymerizable composition.3. The method of embodiment 1, wherein the polymerizable compositioncomprises from about 25% to about 45% by weight of at least onehydrophilic (meth)acrylamido monomer having 3 to 8 carbon atoms relativeto the total weight of the polymerizable composition.4. The method of any one of embodiments 1 to 3, wherein at least onehydrophilic (meth)acrylamido monomer is (meth)acrylamide, N-methyl(meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-ethyl(meth)acrylamide, N,N-diethyl (meth)acrylamide, N-propyl(meth)acrylamide, N-isopropylacrylamide, N-3-methoxypropyl(meth)acrylamide, N-tert-butylacrylamide, N-2-hydroxyethyl(meth)acrylamide, N,N-bis(2-hydroxyethyl) (meth)acrylamide,N-2-hydroxypropyl (meth)acrylamide, N-3-hydroxypropyl (meth)acrylamide,N-2,3-dihydroxypropyl (meth)acrylamide,N-[tris(hydroxymethyl)methyl]-acrylamide, N-2-aminoethyl(meth)acrylamide, N-2-methylaminoethyl (meth)acrylamide,N-2-ethylaminoethyl (meth)acrylamide, N-2-dimethylaminoethyl(meth)acrylamide, N-3-aminopropyl (meth)acrylamide,N-3-methylaminopropyl (meth)acrylamide, N-3-dimethylaminopropylacrylamide, 2-(meth)acrylamidoglycolic acid, or a combination thereof.5. The method of any one of embodiments 1 to 3, wherein at least onehydrophilic (meth)acrylamido monomer is (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-2-hydroxyethyl (meth)acrylamide, or a combinationthereof.6. The method of any one of embodiments 1 to 3, wherein at least onehydrophilic (meth)acrylamido monomer comprises N,N-dimethyl acrylamide.7. The method of any one of embodiments 1 to 6, wherein thepolymerizable composition comprises from about 1% to about 20% by weightof the organic solvent relative to the total weight of polymerizablecomposition.8. The method of any one of embodiments 1 to 6, wherein thepolymerizable composition comprises from about 2% to about 15% by weightof the organic solvent relative to the total weight of polymerizablecomposition.9. The method of any one of embodiments 1 to 6, wherein thepolymerizable composition comprises from about 3% to about 10% by weightof the organic solvent relative to the total weight of polymerizablecomposition.10. The method of any one of embodiments 1 to 9, wherein the organicsolvent is ethanol, 1-propanol, isopropanol, 1-butanol, sec-butanol,isobutanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol,3-methyl-2-butanol, 2-methyl-1-butanol, 2,2-dimethyl-1-propanol,tert-amyl alcohol, 1-methoxy-2-propanol, 3-ethoxy-1-propanol,1-ethoxy-2-propanol, or a combination thereof.11. The method of any one of embodiments 1 to 10, wherein thepolymerizable composition comprises at least about 100 ppm of theradical scavenger relative to the total weight of the polymerizablecomposition.12. The method of any one of embodiments 1 to 10, wherein thepolymerizable composition comprises at least about 200 ppm of theradical scavenger relative to the total weight of the polymerizablecomposition.13. The method of any one of embodiments 1 to 10, wherein thepolymerizable composition comprises at least about 300 ppm, of theradical scavenger relative to the total weight of the polymerizablecomposition.14. The method of any one of embodiments 1 to 13, wherein the radicalscavenger is a N-oxyl or nitroxide compound, a quinone methide, anitroso compound, phenothiazine, phenols, or a naturally-occurringantioxidant free-radical scavenger.15. The method of any one of embodiments 1 to 13, wherein the radicalscavenger is 4-hydroxy-2,2,6,6,-tetramethyl-1-piperidinyloxy in freeradical form.16. The method of any one of embodiments 1 to 15, wherein thepolymerizable composition in the lens mold in an oven is cured for atleast about 40 minutes.17. The method of any one of embodiments 1 to 15, wherein thepolymerizable composition in the lens mold in an oven is cured for atleast about 50 minutes.18. The method of any one of embodiments 1 to 15, wherein thepolymerizable composition in the lens mold in an oven is cured for atleast about 60 minutes.19. The method of any one of embodiments 1 to 18, wherein thepolymerizable composition in the lens mold is thermally cured in theoven at the curing temperature under a nitrogen environment, wherein thenitrogen environment in the oven is maintained by flowing nitrogen gasthrough the oven at a first flow rate.20. The method of any one of embodiments 1 to 19, wherein the organicsolvent has a boiling point of lower than 105° C., wherein the methodfurther comprises, between steps (3) and (4), the steps of: raising oventemperature to a post-curing temperature of about 110° C. or higherwhile increasing the flow rate of nitrogen gas through the oven to asecond flow rate which is at least about 2.0 folds of the first flowrate; and heating the lens mold with the unprocessed silicone hydrogelcontact lens therewithin in the oven at the post-curing temperatureunder nitrogen gas flow through the oven at the second flow rate for atleast about 30 minutes.21. The method of embodiment 20, wherein the post-curing temperature isat least about 115° C.22. The method of embodiment 20, wherein the post-curing temperature isat least about 120° C.23. The method of any one of embodiments 20 to 22, wherein the secondflow rate is at least about 3.0 folds of the first flow rate.24. The method of any one of embodiments 20 to 22, wherein the secondflow rate is at least about 4.0 folds of the first flow rate.25. The method of any one of embodiments 1 to 24, wherein the lens moldwith the unprocessed silicone hydrogel contact lens therewithin isheated in the oven at the post-curing temperature for at least about 60minutes.26. The method of any one of embodiments 1 to 24, wherein the lens moldwith the unprocessed silicone hydrogel contact lens therewithin isheated in the oven at the post-curing temperature for at least about 90minutes.27. The method of any one of embodiments 1 to 24, wherein the lens moldwith the unprocessed silicone hydrogel contact lens therewithin isheated in the oven at the post-curing temperature for at least about 120minutes.28. The method of any one of embodiments 1 to 27, wherein the sum of theamounts of components (a) to (d) is at least about 90% by weightrelative to the total weight of the polymerizable composition.29. The method of any one of embodiments 1 to 27, wherein the sum of theamounts of components (a) to (d) is at least about 93% by weightrelative to the total weight of the polymerizable composition.30. The method of any one of embodiments 1 to 27, wherein the sum of theamounts of components (a) to (d) is at least about 95% by weightrelative to the total weight of the polymerizable composition.31. The method of any one of embodiments 1 to 27, wherein the sum of theamounts of components (a) to (d) is at least about 98% by weightrelative to the total weight of the polymerizable composition.32. The method of any one of embodiments 1 to 31, wherein said at leastone siloxane-containing vinylic monomer is a vinylic monomer of formula(M1) or (M2)

in which: a1 is zero or 1; R_(o) is H or methyl; X_(o) is O or NR₁; L₁is a C₂₋₈ alkylene divalent radical or a divalent radical of

L₁′ is a C₂-C₈ alkylene divalent radical which has zero or one hydroxylgroup; L₁″ is C₃-C₈ alkylene divalent radical which has zero or onehydroxyl group; X₁ is O, NR₁, NHCOO, OCONH, CONR₁, or NR₁CO; R₁ is H ora C₁-C₄ alkyl having 0 to 2 hydroxyl group; R_(t1) and R_(t2)independent of each other are a C₁-C₄ alkyl; X₁′ is O or NR₁; q1 is aninteger of 1 to 20; q2 is an integer of 0 to 20; n1 is an integer of 3to 25; and r1 is an integer of 2 or 3.33. The method of any one of embodiments 1 to 31, wherein said at leastone siloxane-containing vinylic monomer istris(trimethylsilyloxy)silylpropyl (meth)acrylate,[3-(meth)acryloxy-2-hydroxypropyloxy]propylbis(trimethylsiloxy)methylsilane,[3-(meth)acryloxy-2-hydroxypropyloxy]propylbis(trimethylsiloxy)butylsilane,3-(meth)acryloxy-2-(2-hydroxyethoxy)-propyloxy)propylbis(trimethylsiloxy)methylsilane,3-(meth)acryloxy-2-hydroxypropyloxy) propyltris(trimethylsiloxy)silane,N-[tris(trimethylsiloxy)silylpropyl]-(meth)acrylamide,N-(2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)propyloxy)-propyl)-2-methyl(meth)acrylamide,N-(2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)-propyloxy)propyl)(meth)acrylamide,N-(2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)-propyloxy)propyl)-2-methylacrylamide,N-(2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)-propyloxy)propyl)(meth)acrylamide,N-[tris(dimethylpropylsiloxy)silylpropyl]-(meth)acrylamide,N-[tris(dimethylphenylsiloxy) silylpropyl] (meth)acrylamide,N-[tris(dimethylethylsiloxy)silylpropyl] (meth)acrylamide,N,N-bis[2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)propyloxy)propyl]-2-methyl(meth)acrylamide, N,N-bis[2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)propyloxy)-propyl] (meth)acrylamide,N,N-bis[2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)propyloxy)-propyl]-2-methyl(meth)acrylamide,N,N-bis[2-hydroxy-3-(3-(tris(trimethylsilyloxy)-silyl)propyloxy)propyl](meth)acrylamide,N-[2-hydroxy-3-(3-(t-butyldimethylsilyl)-propyloxy)propyl]-2-methyl(meth)acrylamide,N-[2-hydroxy-3-(3-(t-butyldimethylsilyl)propyloxy)propyl](meth)acrylamide,N,N-bis[2-hydroxy-3-(3-(t-butyldimethylsilyl)propyloxy)propyl]-2-methyl(meth)acrylamide,N-2-(meth)acryloxyethyl-O-(methyl-bis-trimethylsiloxy-3-propyl)silylcarbamate, 3-(trimethylsilyl)propylvinyl carbonate,3-(vinyloxycarbonylthio)-propyl-tris(trimethyl-siloxy)silane,3-[tris(trimethylsiloxy)silyl]propylvinyl carbamate,3-[tris(trimethylsiloxy)silyl] propyl allyl carbamate,3-[tris(trimethylsiloxy)silyl]propyl vinyl carbonate, or a combinationthereof.34. The method of any one of embodiments 1 to 31, wherein said at leastone siloxane-containing vinylic monomer istris(trimethylsilyloxy)silylpropyl (meth)acrylate,[3-(meth)acryloxy-2-hydroxypropyloxy]propylbis(trimethylsiloxy)methylsilane,[3-(meth)acryloxy-2-hydroxypropyloxy]propylbis(trimethylsiloxy)butylsilane,3-(meth)acryloxy-2-(2-hydroxyethoxy)-propyloxy)propylbis(trimethylsiloxy)methylsilane,3-(meth)acryloxy-2-hydroxypropyloxy)propyltris(trimethylsiloxy)silane,or a combination thereof.35. The method of any one of embodiments 1 to 31, wherein said at leastone siloxane-containing vinylic monomer isN-[tris(trimethylsiloxy)silylpropyl]-(meth)acrylamide,N-(2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)propyloxy)-propyl)-2-methyl (meth)acrylamide,N-(2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)-propyloxy)propyl)(meth)acrylamide,N-(2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)-propyloxy)propyl)-2-methylacrylamide,N-(2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)-propyloxy)propyl)(meth)acrylamide, or a combination thereof.36. The method of any one of embodiments 1 to 31, wherein said at leastone siloxane-containing vinylic monomer is α-(meth)acryloxypropylterminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-(meth)acryloxy-2-hydroxypropyloxypropyl terminated ω-C₁-C₄-alkylterminated polydimethylsiloxane,α-(2-hydroxyl-methacryloxypropyloxypropyl)-ω-C₁-C₄-alkyl-decamethylpentasiloxane,α-[3-(meth)acryloxyethoxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxy-propyloxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxyisopropyloxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxybutyloxy-2-hydroxypropyloxypropyl]-terminatedω—C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxyethylamino-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxypropylamino-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloxy-butylamino-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[(meth)acryloxy(polyethylenoxy)-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[(meth)acryloxy-2-hydroxypropyloxy-ethoxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[(meth)acryloxy-2-hydroxypropyl-N-ethylaminopropyl]-terminatedω—C₁-C₄-alkyl terminated polydimethylsiloxane,α-[(meth)acryloxy-2-hydroxypropyl-aminopropyl]-terminated ω-C₁-C₄-alkylterminated polydimethylsiloxane,α-[(meth)acryloxy-2-hydroxypropyloxy-(polyethylenoxy)propyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-(meth)acryloylamidopropyloxypropyl terminated ω-C₁-C₄-alkyl terminatedpolydimethylsiloxane, α-N-methyl-(meth)acryloylamidopropyloxypropylterminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acrylamidoethoxy-2-hydroxypropyloxy-propyl]-terminatedω-C₁-C₄-alkyl polydimethylsiloxane,α-[3-(meth)acrylamidopropyloxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acrylamidoisopropyloxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acrylamidobutyloxy-2-hydroxypropyloxypropyl]-terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,α-[3-(meth)acryloylamido-2-hydroxypropyloxypropyl] terminatedω-C₁-C₄-alkyl polydimethylsiloxane,α-[3-[N-methyl-(meth)acryloylamido]-2-hydroxypropyloxypropyl]terminatedω-C₁-C₄-alkyl terminated polydimethylsiloxane,N-methyl-N′-(propyltetra(dimethylsiloxy)dimethylbutylsilane)(meth)acrylamide,N-(2,3-dihydroxypropane)-N′-(propyltetra(dimethylsiloxy)dimethylbutylsilane)(meth)acrylamide,(meth)acryloylamidopropyltetra(dimethylsiloxy)dimethylbutylsilane,α-vinyl carbonate-terminated ω-C₁-C₄-alkyl-terminatedpolydimethylsiloxanes, α-vinyl carbamate-terminatedω—C₁-C₄-alkyl-terminated polydimethylsiloxane, or a mixture thereof.37. The method of any one of embodiments 1 to 36, wherein said at leastone polysiloxane vinylic crosslinker is a vinylic crosslinker of formula(I)

in which:ν1 is an integer of from 30 to 500 and 031 is an integer of from 1 to75, provided that ω1/ν1 is from about 0.035 to about 0.15;X₀₁ is O or NR_(N) in which R_(N) is hydrogen or C₁-C₁₀-alkyl;R_(o) is hydrogen or methyl;R_(I1) and R_(I2) independently of each other are a substituted orunsubstituted C₁-C₁₀ alkylene divalent radical or a divalent radical of—R_(I4)—O—R_(I5)— in which R_(I4) and R_(I5) independently of each otherare a substituted or unsubstituted C₁-C₁₀ alkylene divalent radical;R_(I3) is a monovalent radical of any one of formula (Ia) to (Ie)

p1 is zero or 1; m1 is an integer of 2 to 4; m2 is an integer of 1 to 5;m3 is an integer of 3 to 6; m4 is an integer of 2 to 5;R_(I6) is hydrogen or methyl;R_(I7) is a C₂-C₆ hydrocarbon radical having (m2+1) valencies;R_(I8) is a C₂-C₆ hydrocarbon radical having (m4+1) valencies;R_(I9) is ethyl or hydroxymethyl;R_(I10) is methyl or hydromethyl;R_(I11) is hydroxyl or methoxy;X_(I1) is a sulfur linkage of —S— or a teriary amino linkage of—NR_(I12)— in which R_(I12) is C₁-C₁ alkyl, hydroxyethyl, hydroxypropyl,or 2,3-dihydroxypropyl; andX_(I2) is an amide linkage of

in which R_(I13) is hydrogen or C₁-C₁₀ alkyl.38. The method of any one of embodiments 1 to 36, wherein said at leastone polysiloxane vinylic crosslinker is a vinylic crosslinker of formula(A)

in which ν1 is an integer of from 30 to 500 and ω1 is an integer of from1 to 75, provided that ω1/ν1 is from about 0.035 to about 0.15.39. The method of any one of embodiments 1 to 36, wherein said at leastone polysiloxane vinylic crosslinker is a vinylic crosslinker of any oneof formula (1) to (7)

in which:ν1 is an integer of from 30 to 500;ν2 is an integer of from 5 to 50;ν3 is an integer of from 5 to 100;ω2 and ω3 independent of each other are an integer of from 1 to 15;a1 and g1 independent of each other is zero or 1;h1 is an integer of 1 to 20 and h2 is an integer of 0 to 20;m1 and m3 independent of each other is 0 or 1, m2 is an integer of 1 to6, m4 is an integer of 1 to 5, m5 is 2 or 3;q1 is an integer of 1 to 20, q2 is an integer of 0 to 20, q3 is aninteger of 0 to 2, q4 is an integer of 2 to 50, q5 and q6 independent ofeach other are a number of 0 to 35, provided that (q4+q5+q6) is aninteger of 2 to 50;x+y is an integer of from 10 to 30;e1 is an integer of 5 to 100, p1 and b1 independent of each other are aninteger of 0 to 50, provided that (e1+p1+b1)≥10 and e1/(p1+b1)≥2 when(p1+b1)≥1;R_(o) is H or methyl;R₁, R_(1n), R_(2n), R_(3n), and R_(4n) independent of one another are Hor a C₁-C₄ alkyl having 0 to 2 hydroxyl group;R_(n5) is H or a C₁-C₁₀ alkyl;R₂ is a C₄-C₁₄ hydrocarbon divalent radical;R₃ is a C₂-C₆ alkylene divalent radical;R₄ and R₅ independent of each other are a C₁-C₆ alkylene divalentradical or a C₁-C₆ alkylene-oxy-C₁-C₆ alkylene divalent radical;R₆ and R₇ independent of each other are a C₁-C₆ alkylene divalentradical or a C₁-C₆ alkoxy-C₁-C₆ alkylene divalent radical;R₈ and R₉ independent of each other are a substituted or unsubstitutedC₁-C₂ alkylene divalent radical;X_(o), X₁′, X_(o1), X₀₂, and X₀₃ independent of one another are O orNR₁;X₁ is O, NR₁, NHCOO, OCONH, CONR₁, or NR₁CO;X_(o4) is —COO— or —CONR_(n5)—;X_(o5) and X_(o7) independent of each other are a direct bond, —COO— or—CONR_(n5)—;X_(o6) is a direct bond, a C₁-C₆ alkylene divalent radical, a C₁-C₆alkylenoxy divalent radical, —COO—, or —CONR_(n5)—;X_(o8) is a direct bond or —COO—;X_(o9) is O or NR_(n5);X₁₀ is a direct bond, a C₁-C₆ alkylene divalent radical, —COO—, or—CONR_(n5)—;E₁′ is a monovalent radical of

E₂ is a monovalent radical of

E₃ is a monovalent radical of

E₄ is a monovalent radical of

L₁ is a C₂-C₈ alkylene divalent radical or a divalent radical of

L₁′ is a C₂-C₈ alkylene divalent radical which has zero or one hydroxylgroup;L₁″ is C₃-C₈ alkylene divalent radical which has zero or one hydroxylgroup;L₃ is a divalent radical of

in which PE is a divalent radical of

L₃′ is C₃-C₈ alkylene divalent radical;L₄ is a divalent radical of

hpL₁ is a divalent radical of

hpL₂ is a divalent radical of

hpL₃ is a divalent radical of

hpL₄ is a divalent radical of

pOAlk is a divalent radical of

in which EO is an oxyethylene unit (—CH₂CH₂O—), PO is an oxypropyleneunit

and BO is an oxybutylene unit

M₀ is C₃-C₈ alkylene divalent radical;M₁ is a C₄-C₁₄ hydrocarbon divalent radical;M₂ and M₃ independent of each other are a C₁-C₆ alkylene divalentradical;J₀ is a C₁-C₂ hydrocarbon radical having 0 to 2 hydroxyl or carboxylgroups;G1 is a direct bond, a C₁-C₄ alkylene divalent radical, or a bivalentradical of

in which M₀ is linked to Si atom while X₀₄ to X₁₀ are linked to thegroup of —CH₂— in formula (7) and at least one of Jo and G1 in formula(7) comprises at least one moieties selected from the group consistingof hydroxyl groups, urethane linkage of —OCONH—, amino groups of—NHR^(o), amino linkages of —NH—, amide linkages of —CONH—, carboxylgroups, and combinations thereof;G₂ is a C₁-C₄ alkylene divalent radical or a bivalent radical of

G₃ is a divalent radical of

in which h3 and h4 independent of each other are 1 or 0;G4 is a divalent radical of any one of (a) —NR₃′— in which R₃′ ishydrogen or C₁-C₃ alkyl, (b)

(c) —NR₀-G₅-NR₀— in which G₅ is a C₁-C₆ alkylene divalent radical,2-hydroxylpropylene divalent radical, 2-(phosphonyloxy)propylenedivalent radical, 1,2-dihydroxyethylene divalent radical,2,3-dihydroxybutylene divalent radical, and (d) —O-G₆-O— in which G₆ isa C₁-C₆ alkylene divalent radical, a divalent radical of

in which h4′ is 1 or 2, a divalent radical of

a divalent radical of

in which h5 is an integer of 1 to 5, a divalent radical of

in which h6 is 2 or 3, or a substituted C₃-C₈ alkylene divalent radicalhaving a hydroxyl group or phosphonyloxy group;Y₁ is a C₁-C₆ alkylene divalent radical, 2-hydroxylpropylene divalentradical, 2-(phosphonyloxy)propylene divalent radical,1,2-dihydroxyethylene divalent radical, a divalent radical of

or a divalent radical of

Y₂ is a divalent radical of

Y₃ is a divalent radical of

Z₀ is a direct bond or a C₁-C₁₂ alkylene divalent radical;Z₁ is a C₁-C₆ alkylene divalent radical, a hydroxyl- ormethoxy-substituted C₁-C₆ alkylene divalent radical, or a substituted orunsubstituted phenylene divalent radical,Z₂ is a C₁-C₆ alkylene divalent radical, a hydroxyl- ormethoxy-substituted C₁-C₆ alkylene divalent radical, a dihydroxyl- ordimethoxy-substituted C₂-C₆ alkylene divalent radical, a divalentradical of —C₂H₄—(O—C₂H₄)_(m2)—, a divalent radical of —Z₄—S—S—Z₄—, ahydroxyl- or methoxy-substituted C₁-C₆ alkylene divalent radical, or asubstituted or unsubstituted phenylene divalent radical,Z₃ is a divalent radical of any one of (a) —NR_(n3)—,

(c) —NR₀—Z₅—NR₀—, and (d) —O—Z₆—O—,Z₄ is a C₁-C₆ alkylene divalent radical,Z₅ is a C₁-C₆ alkylene divalent radical, 2-hydroxylpropylene divalentradical, 2-(phosphonyloxy)propylene divalent radical,1,2-dihydroxyethylene divalent radical, 2,3-dihydroxybutylene divalentradical,Z₆ is (a) a C₁-C₆ alkylene divalent radical, (b) a divalent radical of

or (c) a substituted C₃-C₈ alkylene divalent radical having a hydroxylgroup or phosphonyloxy group,Z₇ is a divalent radical of

andZ₈ is a divalent radical of

40. The method of any one of embodiments 1 to 36, wherein thepolymerizable materials comprise at least one silicone-containingvinylic crosslinker which isα,ω-bis[3-(meth)acrylamidopropyl]-terminated polydimethylsiloxane,α,ω-bis[3-(meth)acryloxypropyl]-terminated polydimethylsiloxane,α,ω-bis[3-(meth)acryloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxyethoxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxypropyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxy-isopropyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxybutyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamidoethoxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane, a,ω-bis[3-(meth)acrylamidopropyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamidoisopropyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamidobutyloxy-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxyethylamino-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxypropylamino-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acryloxybutylamino-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acrylamidoethylamino-2-hydroxypropyloxy-propyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamidopropylamino-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[3-(meth)acrylamide-butylamino-2-hydroxypropyloxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acryloxy-2-hydroxypropyloxy-ethoxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acryloxy-2-hydroxypropyl-N-ethylaminopropyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acryloxy-2-hydroxypropyl-aminopropyl]-polydimethylsiloxane,α,ω-bis[(meth)acryloxy-2-hydroxypropyloxy-(polyethylenoxy)propyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acryloxyethylamino-carbonyloxy-ethoxypropyl]-terminatedpolydimethylsiloxane,α,ω-bis[(meth)acryloxyethylamino-carbonyloxy-(polyethylenoxy)propyl]-terminatedpolydimethylsiloxane, or a combination thereof.41. The method of any one of embodiments 1 to 40, wherein thepolymerizable composition further comprises about 10% or less by weightof one or more polymerizable components selected from the groupconsisting of an N-vinyl amide monomer, a hydrophilic (meth)acryloxymonomer, a hydrophobic acrylic monomer capable of forming a homopolymerwith a T, of at least about 60° C., a non-silicone vinylic crosslinker,and combinations thereof, relative to the total weight of thepolymerizable composition.42. The method of any one of embodiments 1 to 40, wherein thepolymerizable composition further comprises about 8% or less by weightof one or more polymerizable components selected from the groupconsisting of an N-vinyl amide monomer, a hydrophilic (meth)acryloxymonomer, a hydrophobic acrylic monomer capable of forming a homopolymerwith a T, of at least about 60° C., a non-silicone vinylic crosslinker,and combinations thereof, relative to the total weight of thepolymerizable composition.43. The method of any one of embodiments 1 to 40, wherein thepolymerizable composition further comprises about 6% or less by weightof one or more polymerizable components selected from the groupconsisting of an N-vinyl amide monomer, a hydrophilic (meth)acryloxymonomer, a hydrophobic acrylic monomer capable of forming a homopolymerwith a T, of at least about 60° C., a non-silicone vinylic crosslinker,and combinations thereof, relative to the total weight of thepolymerizable composition.44. The method of any one of embodiments 1 to 40, wherein thepolymerizable composition further comprises about 4% or less by weightor less of one or more polymerizable components selected from the groupconsisting of an N-vinyl amide monomer, a hydrophilic (meth)acryloxymonomer, a hydrophobic acrylic monomer capable of forming a homopolymerwith a T, of at least about 60° C., a non-silicone vinylic crosslinker,and combinations thereof, relative to the total weight of thepolymerizable composition.45. The method of any one of embodiments 41 to 44, wherein thepolymerizable composition comprises N-vinyl amide monomer selected fromthe group consisting of N-vinylpyrrolidone, N-vinyl piperidone, N-vinylcaprolactam, N-vinyl-N-methyl acetamide, N-vinyl formamide, N-vinylacetamide, N-vinyl isopropylamide, N-vinyl-N-methyl acetamide,N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, and mixturesthereof. Preferably, the N-vinyl amide monomer is N-vinylpyrrolidone,N-vinyl-N-methyl acetamide, and combinations thereof.46. The method of any one of embodiments 41 to 45, wherein thepolymerizable composition comprises the hydrophilic (meth)acryloxymonomer selected from the group consisting of 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, glycerol methacrylate (GMA), di(ethylene glycol)(meth)acrylate, tri(ethylene glycol) (meth)acrylate, tetra(ethyleneglycol) (meth)acrylate, poly(ethylene glycol) (meth)acrylate having anumber average molecular weight of up to 1500, ethylene glycol methylether (meth)acrylate, di(ethylene glycol) methyl ether (meth)acrylate,tri(ethylene glycol) methyl ether (meth)acrylate, tetra(ethylene glycol)methyl ether (meth)acrylate, C₁-C₄-alkoxy poly(ethylene glycol)(meth)acrylate having a weight average molecular weight of up to 1500,(meth)acrylic acid, ethylacrylic acid, 2-aminoethyl (meth)acrylate,2-methylaminoethyl (meth)acrylate, 2-ethylaminoethyl (meth)acrylate,3-aminopropyl (meth)acrylate, 3-methylaminopropyl (meth)acrylate,3-ethylaminopropyl (meth)acrylate, 3-amino-2-hydroxypropyl(meth)acrylate, trimethylammonium 2-hydroxy propyl (meth)acrylatehydrochloride, dimethylaminoethyl (meth)acrylate, and combinationsthereof.47. The method of any one of embodiments 41 to 46, wherein thepolymerizable composition comprises the hydrophobic acrylic monomerselected from the group consisting of methyl methacrylate, ethylmethacrylate, isopropyl methacrylate, sec-butyl methacrylate, tert-butylmethacrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornylmethacrylate, phenyl methacrylate, 4-tert-butylstyrene, 2-methylstyrene,styrene, 4-ethoxystyrene, 2,4-dimethystyrene, 2,5-dimethylstyrene,3,5-dimethylstyrene, and combinations thereof.48. The method of any one of embodiments 41 to 46, wherein thepolymerizable composition comprises the hydrophobic acrylic monomerselected from the group consisting of methyl methacrylate, tert-butylmethacrylate, or a combination thereof.49. The method of any one of embodiments 41 to 48, wherein thepolymerizable composition comprises from about 1.5% or less by weight ofthe non-silicone vinylic crosslinker relative to the total weight of allpolymerizable components in the polymerizable composition, wherein thenon-silicone vinylic crosslinker is ethyleneglycol di-(meth)acrylate,diethyleneglycol di-(meth)acrylate, triethyleneglycol di-(meth)acrylate,tetraethyleneglycol di-(meth)acrylate, glycerol di-(meth)acrylate,1,3-propanediol di-(meth)acrylate, 1,3-butanediol di-(meth)acrylate,1,4-butanediol di-(meth)acrylate, glycerol 1,3-diglycerolatedi-(meth)acrylate, ethylenebis[oxy(2-hydroxypropane-1,3-diyl)]di-(meth)acrylate, bis[2-(meth)acryloxyethyl] phosphate,trimethylolpropane di-(meth)acrylate, and3,4-bis[(meth)acryloyl]tetrahydrofuan, diacrylamide (i.e.,N-(1-oxo-2-propenyl)-2-propenamide), dimethacrylamide (i.e.,N-(1-oxo-2-methyl-2-propenyl)-2-methyl-2-propenamide),N,N-di(meth)acryloyl-N-methylamine, N,N-di(meth)acryloyl-N-ethylamine,N,N′-methylene bis(meth)acrylamide, N,N′-ethylene bis(meth)acrylamide,N,N′-dihydroxyethylene bis(meth)acrylamide, N,N′-propylenebis(meth)acrylamide, N,N′-2-hydroxypropylene bis(meth)acrylamide,N,N′-2,3-dihydroxybutylene bis(meth)acrylamide,1,3-bis(meth)acrylamide-propane-2-yl dihydrogen phosphate (i.e.,N,N′-2-phophonyloxypropylene bis(meth)acrylamide), piperazinediacrylamide (or 1,4-bis(meth)acryloyl piperazine), tetraethyleneglycoldivinyl ether, triethyleneglycol divinyl ether, diethyleneglycol divinylether, ethyleneglycol divinyl ether, triallyl isocyanurate, triallylcyanurate, trimethylopropane trimethacrylate, pentaerythritoltetramethacrylate, bisphenol A dimethacrylate, or combinations thereof.50. The method of any one of embodiments 41 to 48, wherein thepolymerizable composition comprises from about 1.5% or less by weight ofthe non-silicone vinylic crosslinker relative to the total weight of allpolymerizable components in the polymerizable composition, wherein thenon-silicone vinylic crosslinker is tetra(ethyleneglycol)di-(meth)acrylate, tri(ethyleneglycol) di-(meth)acrylate, ethyleneglycoldi-(meth)acrylate, di(ethyleneglycol) di-(meth)acrylate,tetraethyleneglycol divinyl ether, triethyleneglycol divinyl ether,diethyleneglycol divinyl ether, ethyleneglycol divinyl ether, triallylisocyanurate, triallyl cyanurate, or a combination thereof.51. The method of any one of embodiments 1 to 50, wherein the step (5)of removing is performed, before the unprocessed silicone hydrogelcontact lens is contact with water or any liquid, by (a) bring aultrasonic horn in direct contact with at least one area of anon-optical surface of the lens-adhered mold half having the unprocessedsilicone hydrogel lens precursor attached thereon and (b) applying aultrasonic vibrational energy of from about 0.2 to about 18 J to the atleast one area of the non-optical surface of the lens-adhered mold halfhaving the unprocessed silicone hydrogel contact lens adhered thereon soas to remove the unprocessed silicone hydrogel contact lens from thelens-adhered mold half.52. The method of embodiment 51, wherein the ultrasonic horn has aconvex surface which is in contact with the lens-adhered mold half.53. The method of embodiment 51, wherein the ultrasonic horn has aconcave surface which is in contact with the lens-adhered mold half.54. The method of embodiment 51, wherein the ultrasonic horn has a flatsurface which is in contact with the lens-adhered mold half.55. The method of any one of embodiments 51 to 54, further comprising astep of subjecting the unprocessed silicone hydrogel contact lensobtained in step (5) to one or more post-molding processes selected fromthe group consisting of extraction, hydration, surface treatment,packaging, sterilization, and combinations thereof.

The previous disclosure will enable one having ordinary skill in the artto practice the invention. Various modifications, variations, andcombinations can be made to the various embodiment described herein. Inorder to better enable the reader to understand specific embodiments andthe advantages thereof, reference to the following examples issuggested. It is intended that the specification and examples beconsidered as exemplary.

Example 1 Oxygen Permeability Measurements

The apparent oxygen permeability (Dk_(app)), the apparent oxygentransmissibility (Dk/t), the intrinsic (or edge-corrected) oxygenpermeability (Dk_(o)) of a lens and a lens material are determinedaccording to procedures described in Example 1 of U.S. patentapplication publication No. 2012/0026457 A1 (herein incorporated byreference in its entirety).

Equilibrium Water Content

The equilibrium water content (EWC) of contact lenses is determined asfollows.

Amount of water (expressed as percent by weight) present in a hydratedhydrogel contact lens, which is fully equilibrated in saline solution,is determined at room temperature. Quickly stack the lenses, andtransfer the lens stack to the aluminum pan on the analytical balanceafter blotting lens in a cloth. The number of lenses for each sample panis typically five (5). Record the pan plus hydrated weight of thelenses. Cover the pan with aluminum foil. Place pans in a laboratoryoven at 100±2° C. to dry for 16-18 hours. Remove pan plus lenses fromthe oven and cool in a desiccator for at least 30 minutes. Remove asingle pan from the desiccator, and discard the aluminum foil. Weigh thepan plus dried lens sample on an analytical balance. Repeat for allpans. The wet and dry weight of the lens samples can be calculated bysubtracting the weight of the empty weigh pan.

Elastic Modulus

The elastic modulus of a contact lens is determined using a MTS insightinstrument. The contact lens is first cut into a 3.12 mm wide stripusing Precision Concept two stage cutter. Five thickness values aremeasured within 6.5 mm gauge length. The strip is mounted on theinstrument grips and submerged in PBS with the temperature controlled at21±2° C. Typically 5N Load cell is used for the test. Constant force andspeed is applied to the sample until the sample breaks. Force anddisplacement data are collected by the TestWorks software. The elasticmodulus value is calculated by the TestWorks software which is the slopeor tangent of the stress vs. strain curve near zero elongation, in theelastic deformation region.

Example 2 Preparation of Polymerizable Compositions

All polymerizable compositions (i.e., “formulations”) are prepared atroom temperature in air by blending all the components for 30-120minutes using a magnetic stir plate. Two polymerizable compositions(Control and Testing formulations) are prepared by blending: 38 weightpart units of CE-PDMS (Mn 9 KD) which has three polydimethylsiloxane(PDMS) segments linked via diurethane linkages between two PDMS segmentsand two urethane linkages each located between one terminal methacrylategroup and one PDMS segment and is prepared according to method similarto what described in Example 2 of U.S. Pat. No. 8,529,057; 28 weightpart units of TrisAm (N-[tris(trimethylsiloxy)-silylpropyl]acrylamide);34 weight part units of DMA (N,N-dimethylacrylamide); 0.5 weight partunit of Vazo-64; zero (control formulation) or 400 ppm (testingformulation) of H-TEMPO (4-hydroxy-2,2,6,6,-tetramethyl-1-piperidinyloxyin free radical form).

Differential Scanning Calorimetry (DSC) Studies

Polymerization kinetics (or curing kinetics) of both the lensformulations prepared above is studied with DSC. The control formulationshows a mono-phase curing profile (i.e., one peak shown in the plot ofHeat flow (W/g) as function of time) at a temperature of 90° C. or 100°C. The testing formulation shows a bi-phase curing profile (i.e., twopeaks shown in the plot of Heat flow (W/g) as function of time) at atemperature of 90° C. or 100° C.

Cast Molding Including Curing and Post-Curing Treatment

A lens formulation is purged with nitrogen at room temperature for 30 to35 minutes. The N₂-purged lens formulation is introduced intopolypropylene molds and the molds are closed and placed in an oven. Theoven is configured as follows: a nitrogen supply is connected to theoven through a higher flow capacity controller which can control theflow rate of nitrogen through the oven; at the exhaust line of the oven,vacuum pumps are connected to control the differential pressure of theoven.

The polymerizable compositions in the molds are thermally cured in theoven under the following conditions: (1) purging the oven for about 60minutes by flowing nitrogen through the oven at a flow rate (e.g., 60cubic foot per hour); (2) ramping from room temperature to a curingtemperature (e.g., 90° C.) and then holding at the curing temperaturefor about 60 minutes while keeping nitrogen gas flow at a flow rate(e.g., 40 cubic foot per hour); and (3) cooling from the curingtemperature to room temperature before opening the oven and removing themolds from the oven.

Mold Separation

Lens molds each with a molded silicone hydrogel contact lens precursortherein are mechanically opened as illustrated by FIG. 2 and describedabove. The molded unprocessed silicone hydrogel contact lens precursorsadhere to the male mold halves.

Removing Lens Precursors from Lens-Adhered Mold Halves Moldedunprocessed silicone hydrogel contact lenses are removed (i.e.,“delensed”) from lens-adhered male mold halves by using an ultrasonicwelding apparatus as illustrated in FIG. 3. An ultrasonic horn made ofstainless steel and having a shape shown in FIGS. 4 and 5. Theultrasonic vibration energy used in delensing is about 8 J. The triggerforce is about 100 N.

The silicone hydrogel contact lenses removed from lens-adhered moldhalves are subjected to extraction (with 1-propanol), hydration,packaged in phosphate-buffered saline (pH around 7.2) in a polypropylenepackage, and autoclaved at about 120° C. for 45 minutes. The oxygenpermeability, equilibrium water content, modulus, and elongation atbreak of the obtained silicone hydrogel contact lenses are determinedand reported in Table 1.

TABLE 1 SiHy Contact Lenses Cast-Molded From Control Lens FormulationTesting Lens Formulation DKc (Barrer) 135.9 ± 2.4  146 ± 1.3  Water %32.77 30.11 Modulus (MPa) 0.91 ± 0.02 0.95 ± 0.02 Elongation (%) 220 ±43  199 ± 56 The presence of H-TEMPO in the polymerizable composition providescast-molded SiHy lenses with an enhanced oxygen permeability (i.e., anincrease of about 10 Barrers in oxygen permeability) without significantchanges in mechanical properties (e.g., modulus, or elongation atbreak).

Example 3 Preparation of Polymerizable Compositions

All polymerizable compositions (i.e., “formulations”) are prepared atroom temperature in air by blending all the components for 30-120minutes using a magnetic stir plate. Two polymerizable compositions(Control and Testing formulations) are prepared by dissolving andblending: 38 weight part units of CE-PDMS (Mn 9 KD) of Example 2; 28weight part units of TrisAm; 34 weight part units of DMA; 0.5 weightpart unit of Vazo-64; zero (control formulation) or 200 ppm (testingformulation) of H-TEMPO; and 5 weight part units of 1-PrOH (1-propanol).

Cast Molding Including Curing and Post-Curing Treatment

The lens formulation is introduced into polypropylene molds and themolds are closed and placed in an oven. The oven is configured asfollows: a nitrogen supply is connected to the oven through a higherflow capacity controller which can control the flow rate of nitrogenthrough the oven; at the exhaust line of the oven, vacuum pumps areconnected to control the differential pressure of the oven.

The polymerizable compositions in the molds are thermally cured in theoven under the following conditions: (1) purging the oven for about 60minutes by flowing nitrogen through the oven at a flow rate (e.g., 60cubic foot per hour); (2) ramping from room temperature to a firstcuring temperature (e.g., 55° C.) and then holding at the curingtemperature for about 40 minutes while keeping nitrogen gas flow at aflow rate (e.g., 40 cubic foot per hour); (3) ramping from roomtemperature to a second curing temperature (e.g., 80° C.) and thenholding at the curing temperature for about 40 minutes while keepingnitrogen gas flow at a flow rate (e.g., 40 cubic foot per hour); (4)ramping from room temperature to a third curing temperature (e.g., 100°C.) and then holding at the curing temperature for about 40 minuteswhile keeping nitrogen gas flow at a flow rate (e.g., 40 cubic foot perhour); and (5) cooling from the curing temperature to room temperaturebefore opening the oven and removing the molds from the oven.

Mold Separation

Lens molds each with a molded silicone hydrogel contact lens precursortherein are mechanically opened according to the procedures described inExample 2. The molded unprocessed silicone hydrogel contact lensprecursors adhere to the male mold halves.

Removing Lens Precursors from Lens-Adhered Mold Halves

Molded unprocessed silicone hydrogel contact lenses are removed (i.e.,“delensed”) from lens-adhered male mold halves according the proceduredescribed in Example 2.

The silicone hydrogel contact lenses removed from lens-adhered moldhalves are subjected to extraction (with isopropanol), hydration,packaged in phosphate-buffered saline (pH around 7.2) in a polypropylenepackage, and autoclaved at about 120° C. for 45 minutes. The oxygenpermeability, equilibrium water content, modulus, and elongation atbreak of the obtained silicone hydrogel contact lenses are determinedand reported in Table 2.

TABLE 2 SiHy Contact Lenses Cast-Molded From Control Lens FormulationTesting Lens Formulation DKc (Barrer) 113.2 ± 0.2 122.4 ± 2.1 Water %33.8 34.3 Modulus (MPa) N/A N/A Elongation (%) N/A N/A

Example 4 Preparation of Polymerizable Compositions

All polymerizable compositions (i.e., “formulations”) are prepared atroom temperature in air by blending all the components for 30-120minutes using a magnetic stir plate. Two polymerizable compositions(Control and Testing formulations) are prepared by blending: 41 weightpart units of CE-PDMS (Mn 9000 g/mol) of Example 2; 28 weight part unitsof TrisAm; 31 weight part units of DMA; 0.5 weight part unit of Vazo-64;zero (control formulation) or 200 ppm (testing formulation) of H-TEMPO.

Cast Molding Including Curing and Post-Curing Treatment

The lens formulation is introduced into polypropylene molds and themolds are closed and placed in an oven. The oven is configured asfollows: a nitrogen supply is connected to the oven through a higherflow capacity controller which can control the flow rate of nitrogenthrough the oven; at the exhaust line of the oven, vacuum pumps areconnected to control the differential pressure of the oven.

The polymerizable compositions in the molds are thermally cured in theoven under the following conditions: (1) purging the oven for about 60minutes by flowing nitrogen through the oven at a flow rate (e.g., 60cubic foot per hour); (2) ramping from room temperature to a firstcuring temperature (e.g., 55° C.) and then holding at the curingtemperature for about 40 minutes while keeping nitrogen gas flow at aflow rate (e.g., 40 cubic foot per hour); (3) ramping from roomtemperature to a second curing temperature (e.g., 80° C.) and thenholding at the curing temperature for about 40 minutes while keepingnitrogen gas flow at a flow rate (e.g., 40 cubic foot per hour); (4)ramping from room temperature to a third curing temperature (e.g., 100°C.) and then holding at the curing temperature for about 40 minuteswhile keeping nitrogen gas flow at a flow rate (e.g., 40 cubic foot perhour); and (5) cooling from the curing temperature to room temperaturebefore opening the oven and removing the molds from the oven.

Mold Separation

Lens molds each with a molded silicone hydrogel contact lens precursortherein are mechanically opened according to the procedures described inExample 2. The molded unprocessed silicone hydrogel contact lensprecursors adhere to the male mold halves.

Removing Lens Precursors from Lens-Adhered Mold Halves

Molded unprocessed silicone hydrogel contact lenses are removed (i.e.,“delensed”) from lens-adhered male mold halves according the proceduredescribed in Example 2.

The silicone hydrogel contact lenses removed from lens-adhered moldhalves are subjected to extraction (with isopropanol), hydration,packaged in phosphate-buffered saline (pH around 7.2) in a polypropylenepackage, and autoclaved at about 120° C. for 45 minutes. The oxygenpermeability, equilibrium water content, modulus, and elongation atbreak of the obtained silicone hydrogel contact lenses are determinedand reported in Table 3.

TABLE 3 SiHy Contact Lenses Cast-Molded From Control Lens FormulationTesting Lens Formulation DKc (Barrer) 130.3 ± 2.4 139.1 ± 2.0 Water %27.5 28.4 Modulus (MPa) 1.47 1.42 Elongation (%) 180 227

All the publications and patents which have been cited herein above arehereby incorporated by reference in their entireties.

What is claimed is:
 1. A method for producing silicone hydrogel contact lenses, comprising the steps of: (1) obtaining a polymerizable composition which is clear at room temperature, wherein the polymerizable composition comprises (a) at least one siloxane-containing vinylic monomer, (b) at least one polysiloxane vinylic crosslinker, (c) from about 15% to about 55% by weight of at least one hydrophilic (meth)acrylamido monomer having 3 to 8 carbon atoms, (d) from 0 to about 25% by weight of an organic solvent having relative to the total weight of the polymerizable composition, wherein the organic solvent has 2 to 8 carbon atoms, (e) at least one thermal free radical initiator, and (f) at least one radical scavenger present in an amount for providing the polymerizable composition with a bi-phase curing profile determined by using thermal DSC to polymerization kinetics of the polymerizable composition at a curing temperature of from about 45° C. to about 100° C. as function of time; (2) introducing the polymerizable composition into a lens mold, wherein the lens mold comprises a male mold half having a first molding surface and a female mold half having a second molding surface, wherein the male and female mold halves are configured to receive each other such that a mold cavity is formed between the first and second molding surfaces when the mold is closed; (3) curing thermally the polymerizable composition in the lens mold in an oven at the curing temperature for at least 30 minutes to form an unprocessed silicone hydrogel lens contact lens; (4) separating the lens mold the male and female mold halves, with the unprocessed silicone hydrogel contact lens being adhered on a lens-adhered mold half which is one of the male and female mold halves; and (5) removing the unprocessed silicone hydrogel contact lens from the lens-adhered mold half.
 2. The method of claim 1, wherein at least one hydrophilic (meth)acrylamido monomer is (meth)acrylamide, N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-ethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-propyl (meth)acrylamide, N-isopropylacrylamide, N-3-methoxypropyl (meth)acrylamide, N-tert-butylacrylamide, N-2-hydroxyethyl (meth)acrylamide, N,N-bis(2-hydroxyethyl) (meth)acrylamide, N-2-hydroxypropyl (meth)acrylamide, N-3-hydroxypropyl (meth)acrylamide, N-2,3-dihydroxypropyl (meth)acrylamide, N-[tris(hydroxymethyl)methyl]-acrylamide, N-2-aminoethyl (meth)acrylamide, N-2-methylaminoethyl (meth)acrylamide, N-2-ethylaminoethyl (meth)acrylamide, N-2-dimethylaminoethyl (meth)acrylamide, N-3-aminopropyl (meth)acrylamide, N-3-methylaminopropyl (meth)acrylamide, N-3-dimethylaminopropyl acrylamide, 2-(meth)acrylamidoglycolic acid, or a combination thereof.
 3. The method of claim 2, wherein the organic solvent is ethanol, 1-propanol, isopropanol, 1-butanol, sec-butanol, isobutanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 3-methyl-2-butanol, 2-methyl-1-butanol, 2,2-dimethyl-1-propanol, tert-amyl alcohol, 1-methoxy-2-propanol, 3-ethoxy-1-propanol, 1-ethoxy-2-propanol, or a combination thereof.
 4. The method of claim 3, wherein the radical scavenger is a N-oxyl or nitroxide compound, a quinone methide, a nitroso compound, phenothiazine, phenols, or a naturally-occurring antioxidant free-radical scavenger.
 5. The method of claim 4, wherein the polymerizable composition in the lens mold is thermally cured in the oven at the curing temperature under a nitrogen environment, wherein the nitrogen environment in the oven is maintained by flowing nitrogen gas through the oven at a first flow rate.
 6. The method of claim 5, wherein the organic solvent has a boiling point of lower than 105° C., wherein the method further comprises, between steps (3) and (4), the steps of: raising oven temperature to a post-curing temperature of about 110° C. or higher while increasing the flow rate of nitrogen gas through the oven to a second flow rate which is at least about 2.0 folds of the first flow rate; and heating the lens mold with the unprocessed silicone hydrogel contact lens therewithin in the oven at the post-curing temperature under nitrogen gas flow through the oven at the second flow rate for at least about 30 minutes.
 7. The method of claim 6, wherein the lens mold with the unprocessed silicone hydrogel contact lens therewithin is heated in the oven at the post-curing temperature for at least about 60 minutes.
 8. The method of claim 7, wherein the sum of the amounts of components (a) to (d) is at least about 90% by weight relative to the total weight of the polymerizable composition.
 9. The method of claim 8, wherein the step (5) of removing is performed, before the unprocessed silicone hydrogel contact lens is contact with water or any liquid, by (a) bring a ultrasonic horn in direct contact with at least one area of a non-optical surface of the lens-adhered mold half having the unprocessed silicone hydrogel lens precursor attached thereon and (b) applying a ultrasonic vibrational energy of from about 0.2 to about 18 J to the at least one area of the non-optical surface of the lens-adhered mold half having the unprocessed silicone hydrogel contact lens adhered thereon so as to remove the unprocessed silicone hydrogel contact lens from the lens-adhered mold half.
 10. The method of claim 9, wherein the ultrasonic horn has a convex surface which is in contact with the lens-adhered mold half.
 11. The method of claim 9, wherein the ultrasonic horn has a concave surface which is in contact with the lens-adhered mold half.
 12. The method of claim 9, wherein the ultrasonic horn has a flat surface which is in contact with the lens-adhered mold half.
 13. The method of claim 9, further comprising a step of subjecting the unprocessed silicone hydrogel contact lens obtained in step (5) to one or more post-molding processes selected from the group consisting of extraction, hydration, surface treatment, packaging, sterilization, and combinations thereof.
 14. The method of claim 9, wherein the polymerizable composition further comprises about 10% or less by weight of one or more polymerizable components selected from the group consisting of an N-vinyl amide monomer, a hydrophilic (meth)acryloxy monomer, a hydrophobic acrylic monomer capable of forming a homopolymer with a T, of at least about 60° C., a non-silicone vinylic crosslinker, and combinations thereof, relative to the total weight of the polymerizable composition, wherein the N-vinyl amide monomer is selected from the group consisting of N-vinylpyrrolidone, N-vinyl piperidone, N-vinyl caprolactam, N-vinyl-N-methyl acetamide, N-vinyl formamide, N-vinyl acetamide, N-vinyl isopropylamide, N-vinyl-N-methyl acetamide, N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, and mixtures thereof. Preferably, the N-vinyl amide monomer is N-vinylpyrrolidone, N-vinyl-N-methyl acetamide, and combinations thereof, wherein the hydrophilic (meth)acryloxy monomer is selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycerol methacrylate (GMA), di(ethylene glycol) (meth)acrylate, tri(ethylene glycol) (meth)acrylate, tetra(ethylene glycol) (meth)acrylate, poly(ethylene glycol) (meth)acrylate having a number average molecular weight of up to 1500, ethylene glycol methyl ether (meth)acrylate, di(ethylene glycol) methyl ether (meth)acrylate, tri(ethylene glycol) methyl ether (meth)acrylate, tetra(ethylene glycol) methyl ether (meth)acrylate, C₁-C₄-alkoxy poly(ethylene glycol) (meth)acrylate having a weight average molecular weight of up to 1500, (meth)acrylic acid, ethylacrylic acid, 2-aminoethyl (meth)acrylate, 2-methylaminoethyl (meth)acrylate, 2-ethylaminoethyl (meth)acrylate, 3-aminopropyl (meth)acrylate, 3-methylaminopropyl (meth)acrylate, 3-ethylaminopropyl (meth)acrylate, 3-amino-2-hydroxypropyl (meth)acrylate, trimethylammonium 2-hydroxy propyl (meth)acrylate hydrochloride, dimethylaminoethyl (meth)acrylate, and combinations thereof, wherein the hydrophobic acrylic monomer is selected from the group consisting of methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, phenyl methacrylate, 4-tert-butylstyrene, 2-methylstyrene, styrene, 4-ethoxystyrene, 2,4-dimethystyrene, 2,5-dimethylstyrene, 3,5-dimethylstyrene, and combinations thereof.
 15. The method of claim 14, wherein the polymerizable composition comprises from about 1.5% or less by weight of the non-silicone vinylic crosslinker relative to the total weight of all polymerizable components in the polymerizable composition, wherein the non-silicone vinylic crosslinker is ethyleneglycol di-(meth)acrylate, diethyleneglycol di-(meth)acrylate, triethyleneglycol di-(meth)acrylate, tetraethyleneglycol di-(meth)acrylate, glycerol di-(meth)acrylate, 1,3-propanediol di-(meth)acrylate, 1,3-butanediol di-(meth)acrylate, 1,4-butanediol di-(meth)acrylate, glycerol 1,3-diglycerolate di-(meth)acrylate, ethylenebis[oxy(2-hydroxypropane-1,3-diyl)] di-(meth)acrylate, bis[2-(meth)acryloxyethyl] phosphate, trimethylolpropane di-(meth)acrylate, and 3,4-bis[(meth)acryloyl]tetrahydrofuan, diacrylamide (i.e., N-(1-oxo-2-propenyl)-2-propenamide), dimethacrylamide (i.e., N-(1-oxo-2-methyl-2-propenyl)-2-methyl-2-propenamide), N,N-di(meth)acryloyl-N-methylamine, N,N-di(meth)acryloyl-N-ethylamine, N,N′-methylene bis(meth)acrylamide, N,N′-ethylene bis(meth)acrylamide, N,N′-dihydroxyethylene bis(meth)acrylamide, N,N′-propylene bis(meth)acrylamide, N,N′-2-hydroxypropylene bis(meth)acrylamide, N,N′-2,3-dihydroxybutylene bis(meth)acrylamide, 1,3-bis(meth)acrylamide-propane-2-yl dihydrogen phosphate (i.e., N,N′-2-phophonyloxypropylene bis(meth)acrylamide), piperazine diacrylamide (or 1,4-bis(meth)acryloyl piperazine), tetraethyleneglycol divinyl ether, triethyleneglycol divinyl ether, diethyleneglycol divinyl ether, ethyleneglycol divinyl ether, triallyl isocyanurate, triallyl cyanurate, trimethylopropane trimethacrylate, pentaerythritol tetramethacrylate, bisphenol A dimethacrylate, or combinations thereof.
 16. The method of claim 14, wherein said at least one siloxane-containing vinylic monomer is tris(trimethylsilyloxy)silylpropyl (meth)acrylate, [3-(meth)acryloxy-2-hydroxypropyloxy]propylbis(trimethylsiloxy) methylsilane, [3-(meth)acryloxy-2-hydroxypropyloxy]propylbis(trimethylsiloxy)butylsilane, 3-(meth)acryloxy-2-(2-hydroxyethoxy)-propyloxy) propylbis(trimethylsiloxy)methylsilane, 3-(meth)acryloxy-2-hydroxypropyloxy)propyltris(trimethylsiloxy)silane, N-[tris(trimethylsiloxy)silylpropyl]-(meth)acrylamide, N-(2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl) propyloxy)-propyl)-2-methyl (meth)acrylamide, N-(2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)-propyloxy) propyl) (meth)acrylamide, N-(2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)-propyloxy) propyl)-2-methyl acrylamide, N-(2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)-propyloxy)propyl) (meth)acrylamide, N-[tris(dimethylpropylsiloxy)silylpropyl]-(meth)acrylamide, N-[tris(dimethylphenylsiloxy) silylpropyl] (meth)acrylamide, N-[tris(dimethylethylsiloxy)silylpropyl] (meth)acrylamide, N,N-bis[2-hydroxy-3-(3-(bis(trimethylsilyloxy) methylsilyl)propyloxy)propyl]-2-methyl (meth)acrylamide, N,N-bis[2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl) propyloxy)-propyl](meth)acrylamide, N, N-bis[2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)propyloxy)-propyl]-2-methyl (meth)acrylamide, N,N-bis[2-hydroxy-3-(3-(tris(trimethylsilyloxy)-silyl)propyloxy)propyl] (meth)acrylamide, N-[2-hydroxy-3-(3-(t-butyldimethylsilyl)-propyloxy)propyl]-2-methyl (meth)acrylamide, N-[2-hydroxy-3-(3-(t-butyldimethylsilyl)propyloxy)propyl] (meth)acrylamide, N,N-bis[2-hydroxy-3-(3-(t-butyldimethylsilyl)propyloxy)propyl]-2-methyl (meth)acrylamide, N-2-(meth)acryloxyethyl-O-(methyl-bis-trimethylsiloxy-3-propyl)silyl carbamate, 3-(trimethylsilyl)propylvinyl carbonate, 3-(vinyloxycarbonylthio)-propyl-tris(trimethyl-siloxy)silane, 3-[tris(trimethylsiloxy)silyl]propylvinyl carbamate, 3-[tris(trimethylsiloxy)silyl] propyl allyl carbamate, 3-[tris(trimethylsiloxy)silyl]propyl vinyl carbonate, or a combination thereof.
 17. The method of claim 14, wherein said at least one siloxane-containing vinylic monomer is tris(trimethylsilyloxy)silylpropyl (meth)acrylate, [3-(meth)acryloxy-2-hydroxypropyloxy]propylbis(trimethylsiloxy) methylsilane, [3-(meth)acryloxy-2-hydroxypropyloxy]propylbis(trimethylsiloxy)butylsilane, 3-(meth)acryloxy-2-(2-hydroxyethoxy)-propyloxy) propylbis(trimethylsiloxy)methylsilane, 3-(meth)acryloxy-2-hydroxypropyloxy)propyltris(trimethylsiloxy)silane, or a combination thereof.
 18. The method of claim 14, wherein said at least one siloxane-containing vinylic monomer is N-[tris(trimethylsiloxy)silylpropyl]-(meth)acrylamide, N-(2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)propyloxy)-propyl)-2-methyl (meth)acrylamide, N-(2-hydroxy-3-(3-(bis(trimethylsilyloxy)methylsilyl)-propyloxy)propyl) (meth)acrylamide, N-(2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)-propyloxy)propyl)-2-methyl acrylamide, N-(2-hydroxy-3-(3-(tris(trimethylsilyloxy)silyl)-propyloxy)propyl) (meth)acrylamide, or a combination thereof.
 19. The method of claim 14, wherein said at least one siloxane-containing vinylic monomer is α-(meth)acryloxypropyl terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-(meth)acryloxy-2-hydroxypropyloxypropyl terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-(2-hydroxyl-methacryloxypropyloxypropyl)-ω-C₁-C₄-alkyl-decamethylpentasiloxane, α-[3-(meth)acryloxyethoxy-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[3-(meth)acryloxy-propyloxy-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[3-(meth)acryloxyisopropyloxy-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[3-(meth)acryloxybutyloxy-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[3-(meth)acryloxyethylamino-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[3-(meth)acryloxypropylamino-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[3-(meth)acryloxy-butylamino-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[(meth)acryloxy(polyethylenoxy)-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[(meth)acryloxy-2-hydroxypropyloxy-ethoxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[(meth)acryloxy-2-hydroxypropyl-N-ethylaminopropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[(meth)acryloxy-2-hydroxypropyl-aminopropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[(meth)acryloxy-2-hydroxypropyloxy-(polyethylenoxy)propyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-(meth)acryloylamidopropyloxypropyl terminated ω—C₁-C₄-alkyl terminated polydimethylsiloxane, α-N-methyl-(meth)acryloylamidopropyloxypropyl terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[3-(meth)acrylamidoethoxy-2-hydroxypropyloxy-propyl]-terminated ω-C₁-C₄-alkyl polydimethylsiloxane, α-[3-(meth)acrylamidopropyloxy-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[3-(meth)acrylamidoisopropyloxy-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[3-(meth)acrylamidobutyloxy-2-hydroxypropyloxypropyl]-terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, α-[3-(meth)acryloylamido-2-hydroxypropyloxypropyl] terminated ω-C₁-C₄-alkyl polydimethylsiloxane, α-[3-[N-methyl-(meth)acryloylamido]-2-hydroxypropyloxypropyl]terminated ω-C₁-C₄-alkyl terminated polydimethylsiloxane, N-methyl-N′-(propyltetra(dimethylsiloxy)dimethyl butylsilane) (meth)acrylamide, N-(2,3-dihydroxypropane)-N′-(propyltetra(dimethylsiloxy)dimethylbutylsilane) (meth)acrylamide, (meth)acryloylamidopropyltetra(dimethylsiloxy)dimethylbutylsilane, α-vinyl carbonate-terminated ω-C₁-C₄-alkyl-terminated polydimethylsiloxanes, α-vinyl carbamate-terminated ω-C₁-C₄-alkyl-terminated polydimethylsiloxane, or a mixture thereof.
 20. The method of claim 14, wherein the polymerizable materials comprise at least one silicone-containing vinylic crosslinker which is α,ω-bis[3-(meth)acrylamidopropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acryloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acryloxy-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acryloxyethoxy-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acryloxypropyloxy-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acryloxy-isopropyloxy-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acryloxybutyloxy-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acrylamidoethoxy-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acrylamidopropyloxy-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acrylamidoisopropyloxy-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acrylamidobutyloxy-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acryloxyethylamino-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acryloxypropylamino-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acryloxybutylamino-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[(meth)acrylamidoethylamino-2-hydroxypropyloxy-propyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acrylamidopropylamino-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[3-(meth)acrylamide-butylamino-2-hydroxypropyloxypropyl]-terminated polydimethylsiloxane, α,ω-bis[(meth)acryloxy-2-hydroxypropyloxy-ethoxypropyl]-terminated polydimethylsiloxane, α,ω-bis[(meth)acryloxy-2-hydroxypropyl-N-ethylaminopropyl]-terminated polydimethylsiloxane, α,ω-bis[(meth)acryloxy-2-hydroxypropyl-aminopropyl]-polydimethylsiloxane, α,ω-bis[(meth)acryloxy-2-hydroxypropyloxy-(polyethylenoxy)propyl]-terminated polydimethylsiloxane, α,ω-bis[(meth)acryloxyethylamino-carbonyloxy-ethoxypropyl]-terminated polydimethylsiloxane, α,ω-bis[(meth)acryloxyethylamino-carbonyloxy-(polyethylenoxy)propyl]-terminated polydimethylsiloxane, or a combination thereof. 